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Car Forum / Chrysler Cars / January 2005Times Have Changed: Cold Starting
Has anyone in the north country noticed that on very cold, below zero F mornings almost every vehicle starts right up. Twenty years ago and back, it was very typical for many if not most cars to die during the starting process. Possible reasons: Near universal use of 5W-30 oils and more common use of synthetics. (10W-40 used to be the most common oil used). More efficient starters. Better battery/charging technology. More common electronic ignitions and distributors. Richard. > Has anyone in the north country noticed that on very cold, below zero F > mornings almost every vehicle starts right up. Twenty years ago and back, it [quoted text clipped - 3 lines] > Near universal use of 5W-30 oils and more common use of synthetics. (10W-40 > used to be the most common oil used). Nope > More efficient starters. Nope > Better battery/charging technology. Nope > More common electronic ignitions and distributors. Nope Its ALL because of multi-port high-pressure electronic fuel injection that can keep the mixture spot-on where it needs to be for any engine temperature, and doesn't depend on fully vaporizing the fuel upstream in the intake manifold. A carburetor has a REALLY hard time keeping the mixture anywhere near optimized in sub-zero temperatures, especially through the starting process where the air flow varies from almost none (cranking) to fairly high (fast idle) in a big hurry. In fact, a carb works by pumping a small puddle of fuel into the manifold before cranking (remember "depress accelerator fully twice and release"?) to aid start up, since it can't possibly add enough fuel during cranking. And once the engine fires, that slug of fuel immediately makes the mixture too rich for a few seconds until it burns out... at which time it *may* go too lean again for a few seconds and the engine may stall if you're not quick enough at fluttering the accelerator pedal to pump more fuel in. Frankly, I kinda miss that spluttering, snorting, shaking process for the first 30 seconds or so after start-up. Sounds really neat on a big-block v8 :-) > > Near universal use of 5W-30 oils and more common use of synthetics. > > (10W-40 used to be the most common oil used). > Nope Actually, Steve, yeah, that is one of the factors in the much greater ease of super-cold starts. You live in Texas. I live in Toronto. That alone makes me more qualified to comment on it than you (which is hardly a fair exchange: You get to have barbecues and mow your lawn in the middle of January, I get to prattle-on about cold starts. No fair.) What's more, I've got direct and recent (last month) experience with the difference oil weight makes in ability and ease of starting an engine from cold. So, shutchyer mouth, you! > Its ALL because of multi-port high-pressure electronic fuel injection Naw, it isn't. That's a major factor, but certainly not the only one. EFI makes newer vehicles much less tricky to start in the very cold, but other factors apply to new and old cars alike. Oils with lower pour points and better cold pumpability, gasolines that burn cleaner (leaving the spark plugs cleaner so they require less arcover voltage), etc. DS >>>Near universal use of 5W-30 oils and more common use of synthetics. >>>(10W-40 used to be the most common oil used). [quoted text clipped - 3 lines] > Actually, Steve, yeah, that is one of the factors in the much greater ease > of super-cold starts. You live in Texas. While I'm sure that the better oils increase cranking speed and allow the engine to start quicker and idle with less effort, I don't think it has anything to do with the sputter/die/restart that everyone used to know about with carbureted cars. I live in Toronto. That alone > makes me more qualified to comment on it than you (which is hardly a fair > exchange: You get to have barbecues and mow your lawn in the middle of > January, I get to prattle-on about cold starts. No fair.) What's more, > I've got direct and recent (last month) experience with the difference oil > weight makes in ability and ease of starting an engine from cold. So, > shutchyer mouth, you! You can come mow my lawn in January ANYTIME, if you miss mowing lawns so much :-p And maybe you can snort some cedar pollen while you're at it so I don't have to breathe it:-) >>Its ALL because of multi-port high-pressure electronic fuel injection > [quoted text clipped - 5 lines] > > DS Again, I don't really disagree, but I don't think any of that has so much to do with start/sputter/die/restart as EFI does. EFI can meter, vaporize, and evenly distribute fuel FAR better at low temperatures than a carburetor can, while at higher temperatures the difference is far less noticeable. Oil thickness, plug condition, and battery power all matter, but those are second or third-order effects compared to the better fuel control from MPEFI. And there's even a noticeable difference beetween low-pressure throttle-body injected cars and moder high-pressure EFI cars in the "cold" weather we get here in Texas, too. TBI cars often gripe and grumble a lot like carbureted cars because the intake manifolds are "wet" and fuel distribution is very poor in cold temps, whereas MPI cars almost never do. > While I'm sure that the better oils increase cranking speed and allow > the engine to start quicker and idle with less effort, I don't think it > has anything to do with the sputter/die/restart that everyone used to > know about with carbureted cars. And I'm telling you, from firsthand experience, that you're wrong on this exact point. With 15w50 Mobil-1 at 20 below (C), it took two or three starts for the engine to stay running. With 5w30 Mobil-1 at 20 below (C) and no other changes, the engine stays running after the first start. Cranking speed is pretty irrelevant unless an engine is so whipped that the compression pressure leaks past the rings so fast that a high cranking speed is needed. GM proved in the early 1960s that a typical passenger car engine (of the day!) would start at cranking speeds as low as 6rpm. > You can come mow my lawn in January ANYTIME, if you miss mowing lawns so > much :-p And maybe you can snort some cedar pollen while you're at it so > I don't have to breathe it:-) Fine. I'll accept payment in trips to Kreuz'. > Cranking speed is pretty irrelevant unless an engine is so whipped that > the compression pressure leaks past the rings so fast that a high cranking > speed is needed. GM proved in the early 1960s that a typical passenger car > engine (of the day!) would start at cranking speeds as low as 6rpm. Hell, my old, but reasonably healthy, '82 Mazda 626 will push-start in third gear with somewhere between three and five feet of roll - not a "fast" roll, either, although it does fire even quicker if I can get up some serious speed before popping the clutch - just "moving" - *MAYBE* 1 or 2 MPH, if that. In reverse, a foot or so of roll, at *WAY* below typical walking speed, and a quick clutch-bump is all it takes to fire it up every time. Dunno what the effective RPM is in either case (too lazy to do the math) but whatever the number, it's obviously sufficient for this beast :) Guess that means it ain't quite whipped yet... :) This saved my bacon one night at about 3 in the AM... Stopped out in the middle of nowhere to watch the Perseid meteor shower dropping something like 80 streaks per minute before continuing on my newspaper route, and when I decided it was time to go, the starter said "Nah, I wanna stay here and watch the sky-show" (Turned out later to be the starter literally falling apart - One of the two long screws that held the end-caps on it had vibrated loose, allowing some flex, which bound the bearings - minor miracle: The screw that fell out dropped into a groove in the engine cradle, where it rode safely until I found it later that day while I was doing the wrenching to change out the starter.) Damn fool me had decided to stop at the bottom of a little valley, or maybe gulley would be the better word, in order to screen out the lights on the horizon that were interfering with viewing the meteors - Great view, but both directions were uphill - Figured I was screwed royally. Grunted and heaved and cussed and sweated, and probably strained something, but finally managed to get the front wheels about 2-3 feet up the forward incline before gravity took over and started pushing me back down the slope. Reached in and set the P-brake, sat down and caught my breath, then turned it on, put it in reverse, mashed the clutch, and released the brake. It started rolling back, exactly as expected. It might have managed to hit the dizzying speed of half a mile an hour by the time I bumped the clutch. The front end was still on the slope when the engine fired up.  SignatureDon Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004. Short form: I'm trashing EVERY E-mail that doesn't contain a password in the subject unless it comes from a "whitelisted" (pre-approved by me) address. See <http://www.sonic.net/~dakidd/main/contact.html> for full details. > > Cranking speed is pretty irrelevant unless an engine is so whipped > > that the compression pressure leaks past the rings so fast that a high > > cranking speed is needed. GM proved in the early 1960s that a typical > > passenger car engine (of the day!) would start at cranking speeds as > > low as 6rpm. > Hell, my old, but reasonably healthy, '82 Mazda 626 will push-start in > third gear with somewhere between three and five feet of roll My '91 Spirit R/T would reliably start by just turning the ignition "on", putting the trans in "Reverse", releasing the parking brake, rolling a few feet down the driveway, then releasing the clutch. Two compressions was all it took. > > > Cranking speed is pretty irrelevant unless an engine is so whipped > > > that the compression pressure leaks past the rings so fast that a high [quoted text clipped - 9 lines] > feet down the driveway, then releasing the clutch. Two compressions was > all it took. Yep, that's about what it takes with this beast of mine. As soon as one cylinder even half-assed fires, the engine is running, and keeps on running until I turn off the key. I *LIKE* that in a vehicle. :) SignatureDon Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004. Short form: I'm trashing EVERY E-mail that doesn't contain a password in the subject unless it comes from a "whitelisted" (pre-approved by me) address. See <http://www.sonic.net/~dakidd/main/contact.html> for full details. my OLD DATSUN 66 or so had a HAND CRANK that went through a hole in the bumber to the fly wheel...hard starting, tired battery, NP even had a "dog" to kick it out after it started.......... opened up some of the "oldtimers" eyes in town, when for chuckles, I crank started it...... it was a bullet proof OLD PICKUP......no comfort, no pep, but was reliable for many miles! even like going mudding.....and easy to find mud here! >>>>Cranking speed is pretty irrelevant unless an engine is so whipped >>>>that the compression pressure leaks past the rings so fast that a high [quoted text clipped - 13 lines] > cylinder even half-assed fires, the engine is running, and keeps on > running until I turn off the key. I *LIKE* that in a vehicle. :) People who haven't been there to see it don't believe me when I tell them this, but under just the right conditions (warm weather, engine recently shut down, and crank landing so that one cylinder is just after TDC), I can occasionally start one of my cars just by turning the key ON (no starter at all). The spark from the electronic ignition powering-up lights off the mixture in that one cylinder, whcih kicks it over enough to start it. I can pretty reliably get it to "kick" enough to visibly move the crank any time I want, but it kicks backwards about half the time because the piston is BTDC and usually only turns the engine very slightly. But once in a blue moon (maybe twice in the past 20 years) the darn thing will kick forward hard enough to start and keep running. Have to go with Daniel on this one.. I can remember some research in the 70's having to do with pour points and cold start/running.. and they found at certain temperatures.. they could crank an engine @ 600rpm and it just wouldn't produce enough power to keep itself running with the heavier oils.. darned if I can find a reference to it on the web though.. don't remember who did it either.. but think it was one of the oil companies. >>While I'm sure that the better oils increase cranking speed and allow >>the engine to start quicker and idle with less effort, I don't think it [quoted text clipped - 5 lines] > starts for the engine to stay running. With 5w30 Mobil-1 at 20 below (C) > and no other changes, the engine stays running after the first start. And, your engine has WHAT type of fuel injection? <cough...> I seriously doubt you'd see as great a difference if it were a 93 Magnum 318 instead of an 89 TBI 318. As I said, TBI has a lot of the same cold-weather fuel distribution and vaporization issues that a carburetor does, and the thicker oil is going to aggravate it a lot more than it would an MPI setup that doesn't puddle fuel in the intake. >>You can come mow my lawn in January ANYTIME, if you miss mowing lawns so >>much :-p And maybe you can snort some cedar pollen while you're at it so >>I don't have to breathe it:-) > > Fine. I'll accept payment in trips to Kreuz'. There's a danger to both of us in that: You'd eat all your profits, and I'd eat myself into a BBQ coma :-p > > With 15w50 Mobil-1 at 20 below (C), it took two or three starts for > > the engine to stay running. With 5w30 Mobil-1 at 20 below (C) and no > > other changes, the engine stays running after the first start. > And, your engine has WHAT type of fuel injection? <cough...> Advanced computer controlled PNDEFI. > >>You can come mow my lawn in January ANYTIME, if you miss mowing lawns > >>so much :-p And maybe you can snort some cedar pollen while you're at > >>it so I don't have to breathe it:-) > > Fine. I'll accept payment in trips to Kreuz'. > There's a danger to both of us in that: You'd eat all your profits, and > I'd eat myself into a BBQ coma :-p And the problem...? >> Has anyone in the north country noticed that on very cold, below zero F >> mornings almost every vehicle starts right up. Twenty years ago and back, [quoted text clipped - 28 lines] > again for a few seconds and the engine may stall if you're not quick > enough at fluttering the accelerator pedal to pump more fuel in. Steve, I hate to agree with Dan but "always", "all", "none", and "never" are almost always the wrong answer. :> Art > Has anyone in the north country noticed that on very cold, below zero F > mornings almost every vehicle starts right up. Twenty years ago and back, it > was very typical for many if not most cars to die during the starting > process. Possible reasons: > [quoted text clipped - 8 lines] > > Richard. The problem that I usually had on older cars was the choke. A light tap on the accelerator was needed to set it. Too much would flood it. Then there was the problem of the choke not disengaging when it should, causing a rich air/fuel mix. EFI and AIS stepper motors pretty much eliminated these problems. One of the most troublesome setups that I had, was a Dodge Caravan with the 2.6 and the Minuki carb. The choke never worked right from day one. -Kirk Matheson > Has anyone in the north country noticed that on very cold, below zero F > mornings almost every vehicle starts right up. Twenty years ago and back, it [quoted text clipped - 11 lines] > > Richard. I think computer controlled fuel injection vs. carburetion is the main reason, but I don't disagree with anything you list above. Matt >> Has anyone in the north country noticed that on very cold, below zero F >> mornings almost every vehicle starts right up. Twenty years ago and back, [quoted text clipped - 14 lines] > I think computer controlled fuel injection vs. carburetion is the main > reason, but I don't disagree with anything you list above. I would suggest that the biggest improvement is the elimination of distributors and hence the much improved insulation of the HT path from the coil to the spark plugs. > Matt > I would suggest that the biggest improvement is the elimination of > distributors and hence the much improved insulation of the HT path from > the coil to the spark plugs. Wrong, unless you were dumb enough to try to start English or Italian cars somewhere other than Tucson, AZ. In article <Pine.GSO.4.58.0501202321040.19185@alumni.engin.umich.edu>, > > I would suggest that the biggest improvement is the elimination of > > distributors and hence the much improved insulation of the HT path from > > the coil to the spark plugs. > > Wrong, unless you were dumb enough to try to start English or Italian cars > somewhere other than Tucson, AZ. I've been to Tucson, it gets dark there at night. That rules out the English cars, no? > > > I would suggest that the biggest improvement is the elimination of > > > distributors and hence the much improved insulation of the HT path > > > from the coil to the spark plugs. > > Wrong, unless you were dumb enough to try to start English or Italian > > cars somewhere other than Tucson, AZ. > I've been to Tucson, it gets dark there at night. That rules out the > English cars, no? Well, it rules out *driving* them. They sometimes don't fail to start after dark there, though. In article <Pine.LNX.4.61.0501201953010.11486@localhost.localdomain>, > I would suggest that the biggest improvement is the elimination of > distributors and hence the much improved insulation of the HT path from > the coil to the spark plugs. Nope. The insulation of the HT path hasn't changed in over 30 years and many modern engines still use distributors and cold start just fine, as the OP opined. Steve Lacker hit the nail on the head, it's the advantages of having a fuel injector right above the intake valve that makes the biggest difference. > In article > <Pine.LNX.4.61.0501201953010.11486@localhost.localdomain>, [quoted text clipped - 4 lines] > > Nope. The insulation of the HT path hasn't changed in over 30 Maybe the insulation has not changed, but removing the distributor is a major change to the HT path. Removing an air gap and a number of connectors (all of which are affected by dirt and damp) is clearly a significant change. > years and many modern engines still use distributors and cold > start just fine, as the OP opined. Many old cars also start just fine, even in cold and wet conditions. They all (well, mostly) started just fine when new. It was always the cars that were marginal in some way that did not start properly. My point is that your premise that (some) new cars with distributors start fine does not negate the point that the distributor is a significant cause of reduction of HT voltage at the plug, especially in wet conditions and especially with older cars that may have dirty distributor caps. In article <Pine.LNX.4.61.0501202248380.14670@localhost.localdomain>, > > In article > > <Pine.LNX.4.61.0501201953010.11486@localhost.localdomain>, [quoted text clipped - 9 lines] > connectors (all of which are affected by dirt and damp) is clearly a > significant change. The rotor air gap increases firing voltage. Comparing spark patterns on an ignition scope, the DIS voltages (all else being equal) are lower, lower ionization voltage and lower voltage across the plug gap compared to a distributor type ignition system. An old tow truck drivers trick when trying to start a stubborn engine in the winter is to pull the coil wire slightly loose from the distributor cap, this increases the voltage output from the coil secondary (greatest gap theory). > > years and many modern engines still use distributors and cold > > start just fine, as the OP opined. > > Many old cars also start just fine, even in cold and wet conditions. They > all (well, mostly) started just fine when new. It was always the cars that > were marginal in some way that did not start properly. Marginal because of neglect, or marginal because of design? Any properly operating ignition system will put out 24 KV from the ignition coil (even breaker points) , that's more than enough spark energy to start an engine no matter how cold it is. It's the intake and fuel system that varied so much that made the difference. > My point is that your premise that (some) new cars with distributors start > fine does not negate the point that the distributor is a significant cause > of reduction of HT voltage at the plug, especially in wet conditions and > especially with older cars that may have dirty distributor caps. Now you're talking about vehicles that aren't properly maintained. A DIS system is just as subject to not working properly due to damp conditions as a conventional system was, maybe more so if the design of the DIS is such that the ignition coil placement necessitates extremely long spark plug wires such as would be found on the early Chevrolet built 60* V-6 engines (2.8 and 3.1) and dirty distributor caps can be directly compared to dirty DIS coils, hell, I see more problems now with carbon tracking on DIS coils than what used to be 30 years ago on distributor caps. You're not making an 'all things equal' comparison. The first PFI GM engines used the exact same ignition system as the previous years carbed versions (Chevy Camaro for example), the cold start characteristics were night and day, the cold start drivability was night and day, the hot drivability characteristics were night and day, it all had to do with how the fuel was handled. In the winter of 81, we were stacking flooded Chevy Citations and Cavaliers up like firewood, in 82 when both vehicles went TBI injection, the problems for a large part went away as long as people followed the proper cold start procedure, the ignition systems were exactly the same. > In article > <Pine.LNX.4.61.0501202248380.14670@localhost.localdomain>, [quoted text clipped - 14 lines] > > The rotor air gap increases firing voltage. How so? > Comparing spark patterns on an ignition scope, the DIS voltages > (all else being equal) are lower, lower ionization voltage and [quoted text clipped - 4 lines] > the distributor cap, this increases the voltage output from the > coil secondary (greatest gap theory). I'm not familiar with this theory, but my EE degree is nearly 20 years old so maybe I just forgot. Can you explain or provide a reference? Matt > > The rotor air gap increases firing voltage. > > How so? An ignition coil does not normally output maximum voltage, but will if the resistance in the secondary circuit is increased, creating a gap that can be jumped essentially is an increase in the circuit resistance, since there is a gap between the rotor and the cap contacts, the firing voltage realized will always be higher than if there is no gap such as with DIS. I may also be wrong on this, but my observations on my ignition scope reveal that firing voltages on conventional ignition systems tend to be a few KV higher than firing voltages on DI systems. > > Comparing spark patterns on an ignition scope, the DIS voltages > > (all else being equal) are lower, lower ionization voltage and [quoted text clipped - 7 lines] > I'm not familiar with this theory, but my EE degree is nearly 20 years > old so maybe I just forgot. Can you explain or provide a reference? The greatest gap theory was authored by Mac VandenBrink in 1965, Mac worked as an EE for many years for Allen Test Products. The only references I know of WRT Mac's theory are on i-ATN, easily found if you're a member. Unfortunately I can not copy them and post them here because all i-ATN posts are copyrighted and doing so would jeopardize my membership standing. I became familiar with Mac's teachings way back in the early 80s when I was a GM dealership mechanic during training on the Allen Smart Scope. >>>The rotor air gap increases firing voltage. >> [quoted text clipped - 6 lines] > and the cap contacts, the firing voltage realized will always be > higher than if there is no gap such as with DIS. I don't see how. The voltage output of the coil is a direct function of the strength of the field around the coil that is collapsing. The strength of the field is a function of the current through the primary of the coil when the field is being established. The field doesn't have any "knowledge" of the resistance in the secondary circuit. Greater resistance in the circuit will result in less current (simple Ohm's law application given the EMF induced by the collapsing field) and thus a weaker spark, not a stronger one. I searched around last night and could find not reference whatsoever to either this theory. > I may also be wrong on this, but my observations on my ignition > scope reveal that firing voltages on conventional ignition > systems tend to be a few KV higher than firing voltages on DI > systems. That could well be. I haven't measurement them personally. However, that isn't what is usually claimed. In any event, the strength of the spark is not a huge factor in starting the car in cold weather. I proper fuel/air mixture will ignite with only a small amount of provocation. The really strong spark is needed in cases where the ratio isn't idea. That is why I can believe that the ignition system on a non-FI car might need to be more robust as it is much harder to ignite a mixture that isn't ideal. >>>Comparing spark patterns on an ignition scope, the DIS voltages >>>(all else being equal) are lower, lower ionization voltage and [quoted text clipped - 17 lines] > when I was a GM dealership mechanic during training on the Allen > Smart Scope. Sorry, but this sounds like cold fusion to me. If this were true, then somebody else somewhere would have researched or commented on it. Thus far I've found zilch. Matt > >>>The rotor air gap increases firing voltage. > >> [quoted text clipped - 15 lines] > and thus a weaker spark, not a stronger one. I searched around last > night and could find not reference whatsoever to either this theory. No, the *current* output from the coil is a direct function of the speed of the collapse. The voltage output is whatever is needed to get that current to flow. Hopefully, the lowest breakdown voltage in the system is the spark plug gap, so that when it's exceeded you get a spark in the combustion chamber. If it's fouled or something, the spark will happen someplace else -- through the plug wire insulation, inside the coil.... The gap in the rotor will cause a higher voltage in the coil, but not over in the spark plug where it's needed. > >>> Comparing spark patterns on an ignition scope, the DIS voltages > >>> (all else being equal) are lower, lower ionization voltage and > >>> lower voltage across the plug gap compared to a distributor type > >>> ignition system. That surprises me. I wouldn't be at all surprised to hear that the voltage was higher at the coil for a conventional ignition system; greater at the plug... I don't see how. > >>> An old tow truck drivers trick when trying to start a stubborn > >>> engine in the winter is to pull the coil wire slightly loose from [quoted text clipped - 4 lines] > >> years old so maybe I just forgot. Can you explain or provide a > >> reference? I've heard of it, but I'd have to think a while to see if I believe it. Yes, you'd get a greater coil voltage this way, but the maximum voltage across the spark gap is determined by its breakdown voltage, not the gap over at the distributor. > > The greatest gap theory was authored by Mac VandenBrink in 1965, Mac > > worked as an EE for many years for Allen Test Products. [quoted text clipped - 9 lines] > then somebody else somewhere would have researched or commented on it. > Thus far I've found zilch. I've heard the theory, though I also can't find a reference to it in a quick search -- at one time, there were products that you'd put on your coil that were basically a wire with a gap in it, based on just this theory. SignatureJoseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605 Department of Computer Science FAX -- (505) 646-1002 New Mexico State University http://www.cs.nmsu.edu/~pfeiffer >>> An old tow truck drivers trick when trying to start a stubborn engine >>> in the winter is to pull the coil wire slightly loose from the >>> distributor cap, this increases the voltage output from the coil >>> secondary (greatest gap theory). >> I'm not familiar with this theory, but my EE degree is nearly 20 years >> old so maybe I just forgot. Can you explain or provide a reference? > I've heard of it, but I'd have to think a while to see if I believe it. > Yes, you'd get a greater coil voltage this way, but the maximum voltage > across the spark gap is determined by its breakdown voltage, not the gap > over at the distributor. The system doesn't know or care *where* in the secondary the gap(s) are. Voltage across the plug gap is determined by the breakdown voltage of the highest-dielectric gap in the secondary. Ordinarily that's the spark plug, but if the plugs are wet and/or dirty, the moisture and/or dirt provides a voltage leakoff path from the center electrode to ground and the spark never occurs. By introducing a high-dielectric gap upstream of the plug gap, secondary voltage is increased such that such leakage paths become less parasitic in absolute terms, and the spark has a greater likelihood of happening. I used to demonstrate this on an old '64 Dart parts car with a whipped engine. The plugs fouled fast on that engine, and cylinders would stop working. I would pull plug wires partway off to create a 1/4" to 1/2" gap between their terminal and the spark plug terminal, and one by one as I did this, those cylinders would come back online. It got noisy under the hood, though (Snap! Snap! Snap! Snap!) The "Spark Intensifier" gadgets that used to be sold by JC Witless, in the back pages of Popular Mechanics, etc., were nothing more than enclosed spark gaps designed to be placed in series with the coil wire. Secondary component life suffered (especially the points!) but they did the same thing as described above. And as previously mentioned, all the reputable spark plug makers have offered series-gap spark plugs over the years. They fell out of favor as gasolines got cleaner and ignitions got stronger. DS >I used to demonstrate this on an old '64 Dart parts car >with a whipped engine. The plugs fouled fast on that [quoted text clipped - 4 lines] >come back online. It got noisy under the >hood, though (Snap! Snap! Snap! Snap!) True. That's a cool phenomenon and one I've only got to work a couple of times. Big plug gaps and monster coil outputs have made that a thing of the past for the most part. Toyota MDT in MO > The system doesn't know or care *where* in the secondary the gap(s) are. > Voltage across the plug gap is determined by the breakdown voltage of the > highest-dielectric gap in the secondary. Ordinarily that's the spark > plug This is the step I'm not seeing in the discussion: voltage across the plug gap should be determined by the breakdown voltage of the plug gap (which is an almost, but not quite, circular statement!). I'm not seeing how increading the breakdown voltage someplace else will increase it across the plug gap. > but if the plugs are wet and/or dirty, the moisture and/or dirt provides a > voltage leakoff path from the center electrode to ground and the spark > never occurs. By introducing a high-dielectric gap upstream of the plug > gap, secondary voltage is increased such that such leakage paths become > less parasitic in absolute terms, and the spark has a greater likelihood > of happening. I think I need one step more detail in the explanation to see how this happens. > I used to demonstrate this on an old '64 Dart parts car with a whipped > engine. The plugs fouled fast on that engine, and cylinders would stop > working. I would pull plug wires partway off to create a 1/4" to 1/2" gap > between their terminal and the spark plug terminal, and one by one as I > did this, those cylinders would come back online. It got noisy under the > hood, though (Snap! Snap! Snap! Snap!) OK... > The "Spark Intensifier" gadgets that used to be sold by JC Witless, in the > back pages of Popular Mechanics, etc., were nothing more than enclosed [quoted text clipped - 4 lines] > They fell out of favor as gasolines got cleaner and ignitions got > stronger. I remember the gadget, but I don't remember it working. SignatureJoseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605 Department of Computer Science FAX -- (505) 646-1002 New Mexico State University http://www.cs.nmsu.edu/~pfeiffer > > The system doesn't know or care *where* in the secondary the gap(s) > > are. Voltage across the plug gap is determined by the breakdown > > voltage of the highest-dielectric gap in the secondary. Ordinarily > > that's the spark plug > This is the step I'm not seeing in the discussion: voltage across the > plug gap should be determined by the breakdown voltage of the plug gap > (which is an almost, but not quite, circular statement!). I'm not > seeing how increading the breakdown voltage someplace else will increase > it across the plug gap. If the secondary voltage is raised by a gap upstream of the plug gap, it's higher *through the whole secondary path*, including at the plug gap. > > The "Spark Intensifier" gadgets that used to be sold by JC Witless, in > > the back pages of Popular Mechanics, etc., were nothing more than [quoted text clipped - 6 lines] > > I remember the gadget, but I don't remember it working. It didn't do anything useful on engines in anything approaching proper repair. It only propped-up neglected or worn-out systems. DS > > > The system doesn't know or care *where* in the secondary the gap(s) > > > are. Voltage across the plug gap is determined by the breakdown [quoted text clipped - 9 lines] > If the secondary voltage is raised by a gap upstream of the plug gap, it's > higher *through the whole secondary path*, including at the plug gap. Not quite clear what higher "through the whole secondary path" would mean... However - first, I misremembered. The coil does indeed have an induced voltage, not the induced current I was remembering. And, it turns out (isn't the web wonderful?) that "The Subsidiary Gap as a Means for Improving Ignition", NACA report 57 (1920), is available at http://naca.larc.nasa.gov/reports/1920/naca-report-57/naca-report-57.pdf The weird thing is that it turns out that the capacitances in the circuit are crucial. Basically, when the voltage is building up to fire across the series gap, a charge is also building up. When it gets to breakdown, this discharges, and a charge builds up across the fouled plug. The voltage across the plug is determined by the charge and the capacitance, and will be much higher than you'd expect from the current and resistance. SignatureJoseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605 Department of Computer Science FAX -- (505) 646-1002 New Mexico State University http://www.cs.nmsu.edu/~pfeiffer >>>>The system doesn't know or care *where* in the secondary the gap(s) >>>>are. Voltage across the plug gap is determined by the breakdown [quoted text clipped - 29 lines] > and the capacitance, and will be much higher than you'd expect from > the current and resistance. Excellent find! I scanned this report briefly, but will have to study it a little later. Looks like that the key issue is controlling the rate of discharge of the coil so that the energy peak will be higher than would be the case discharging through a fouled plug where the leakage would allow broadening of the energy pulse and thus lower the peak. Very interesting and finally some good theory and practice discussed. How did you come across this? I wonder if this still applies to ignitions where the coil is switched via a transistor rather than a contact opening... Matt >> The system doesn't know or care *where* in the secondary the gap(s) >> are. Voltage across the plug gap is determined by the breakdown [quoted text clipped - 6 lines] > seeing how increading the breakdown voltage someplace else will > increase it across the plug gap. As I understand it, once the field in the coil has collapsed and the HT voltage has been generated, that voltage is present until grounded. The bigger the gap to jump, the longer the coil windings have to saturate, and thus the bigger the jolt generated once the field does collapse. >> but if the plugs are wet and/or dirty, the moisture and/or dirt >> provides a voltage leakoff path from the center electrode to ground [quoted text clipped - 5 lines] > I think I need one step more detail in the explanation to see how this > happens. Again, as I understand it, the more more volts, the more likely it will be that some of the current will manage to jump the gap on a sub-optimal spark plug. As always, corrections welcome. SignatureTeGGeR? >>The system doesn't know or care *where* in the secondary the gap(s) are. >>Voltage across the plug gap is determined by the breakdown voltage of the [quoted text clipped - 6 lines] > seeing how increading the breakdown voltage someplace else will > increase it across the plug gap. The problem arises not when the plug resistance is too high, but when its too LOW (fouling providing an alternate conductive path around the gap). The slight conductivity of the fouled plug can prevent the coil from fully saturating, even though its still a realtively high resistance path- ignitiion coils don't generate much current at all, so it doesn't take much "leakage" to prevent it from saturating. Inserting another gap "upstream" of the plug will prevent current from "leaking" through the plug, allow the coil to saturate, and then when the upstream gap breaks over the full voltage suddenly appears at the plug gap and jumps it despite the "leakage" path around the gap. One point that is often left out of these "bigger gap in the circuit" discussions is that most of the *energy* delivered by the ignition system gets released in the spark that is jumping the biggest gap. So... while an extra gap may force the coil secondary voltage high enough to fire a terribly fouled spark plug, the *energy* (and thus the ability to reliably fire a the mixture) delivered to the plug is far less than a CLEAN plug with with absolutely NO other gap in the secondary circuit, and most of the energy is being wasted in that extra gap. IOW- adding spark gaps to the secondary side is a half-assed band-aid for a problem that should be fixed instead of patched. That is also why DIS systems are superior to distributors, even though distributor systems (artificially) force a higher peak voltage in the secondary, all other things being equal. >>>>An old tow truck drivers trick when trying to start a stubborn engine >>>>in the winter is to pull the coil wire slightly loose from the [quoted text clipped - 36 lines] > > DS > One point that is often left out of these "bigger gap in the circuit" > discussions is that most of the *energy* delivered by the ignition [quoted text clipped - 6 lines] > spark gaps to the secondary side is a half-assed band-aid for a problem > that should be fixed instead of patched. Yep. It's a neat trick for getting a recalcitrant, neglected engine started, or wringing every last possible tenth of a mile out of a thoroughly whipped engine, but that's about it. >>>>>The rotor air gap increases firing voltage. >>>> [quoted text clipped - 25 lines] > inside the coil.... The gap in the rotor will cause a higher voltage in > the coil, but not over in the spark plug where it's needed. No, the voltage available is defined by the turns ratio of the transformer (coil). I admit it has been a while since I studied and worked with transformers, but I believe the open circuit voltage will still follow the turns ratio rule when the field collapses. The voltage available depends on the turns ratio, not on the size of any gap in the output (secondary) circuit. If the gap is too large, then no current will flow, however, a very high potential will still exist across the secondary terminals even with zero current. > I've heard of it, but I'd have to think a while to see if I believe > it. Yes, you'd get a greater coil voltage this way, but the maximum > voltage across the spark gap is determined by its breakdown voltage, > not the gap over at the distributor. I've been thinking about it and researching it, and at this point I think it is snake oil. >>>The greatest gap theory was authored by Mac VandenBrink in 1965, Mac >>>worked as an EE for many years for Allen Test Products. [quoted text clipped - 14 lines] > your coil that were basically a wire with a gap in it, based on just > this theory. Yes, outfits like J.C. Whitney sell all sorts of gimmick gadgets like this to an unsuspecting public, but that doesn't make them real. Kind of like the magnets for your fuel lines, etc. Every time they are legimately tested, the results are the same ... they don't work. Matt > No, the voltage available is defined by the turns ratio of the > transformer (coil). I admit it has been a while since I studied and [quoted text clipped - 4 lines] > will flow, however, a very high potential will still exist across the > secondary terminals even with zero current. Matt, what do you suppose the voltage on the primary is when the field collapses? >>No, the voltage available is defined by the turns ratio of the >>transformer (coil). I admit it has been a while since I studied and [quoted text clipped - 7 lines] > Matt, what do you suppose the voltage on the primary is when the > field collapses? It should be the voltage on the primary (probably 12-14 volts) times the turn ratio between the primary and secondary. That is basic transformer theory. This link explains it quite simply. Notice that the voltage on the secondary is a function of the voltage used to "charge" the coil and the turns ratio, and not a function of any air gap on the secondary circuit. http://rds.yahoo.com/S=2766679/K=automotive+ignition+coil+ratio/v=2/SID=w/l=WS1/ R=5/IPC=us/SHE=0/H=3/SIG=11jf4h4fb/EXP=1106533064/*-http%3A//www.jlctech.net/ign .html Matt > > Matt, what do you suppose the voltage on the primary is when the > > field collapses? > > It should be the voltage on the primary (probably 12-14 volts) times the > turn ratio between the primary and secondary. That is basic transformer > theory. You haven't answered the question. Either you know it and have seen (measured) it or you haven't. I'm patient, I'll wait. Take your time. But I'll tell you this, a little practical application will go a whole lot farther than what you learned in college. Take your volt meter, set it on min-max and connect it to the coil of your minivan. Aww hell, let's quit screwing around, go here: http://www.interro.com/wav.htm They give some great examples of exactly what I've been saying. Compare the distributor ignition waveforms to the DI waveforms, notice on the conventional waveforms that the firing voltage AND the spark line voltage are measurably higher than those on a DI system. Look at the waveform labeled DIS waste parade, it shows a very high firing voltage due to there being a gap greater than the spark plug gap (an open in a wire). Of course this can all be dismissed I suppose by simply claiming that Interro is some bogus fly by night outfit because you've never heard of them before. > This link explains it quite simply. That link is about as basic as it gets and in NO way delves into what we're talking about here, and just out of curiosity, what are the authors qualifications? > I've heard of it, but I'd have to think a while to see if I believe > it. Yes, you'd get a greater coil voltage this way, but the maximum > voltage across the spark gap is determined by its breakdown voltage, > not the gap over at the distributor. Not universally, but we're talking about starting a cold engine, slow cranking speed, rich mixture, closed throttle and choke which results in very little pressure inside the cylinder, under those conditions, the .100" (or so) rotor air gap is likely to be dominant over the .035"-.045" spark plug gap. Sorry if what I've said so far lead to any confusion, but the subject is cold starting. > I don't see how. The voltage output of the coil is a direct function of > the strength of the field around the coil that is collapsing. The [quoted text clipped - 5 lines] > weaker spark, not a stronger one. I searched around last night and > could find not reference whatsoever to either this theory. Here's a link to a simple adjustable spark tester: http://thextontools.com/dynamicdata/shop/shopexd.asp?id=299&catid= 35 Notice the scale on the bottom, as the gap is increased, the KV requirement increases. If I'm wrong, then this tool does not work, but I own a version of this tool and have used it with my ignition scope connected and it's pretty much dead nuts on, probably because the dielectric of the air gap is pretty predictable. > > I may also be wrong on this, but my observations on my ignition > > scope reveal that firing voltages on conventional ignition [quoted text clipped - 3 lines] > That could well be. I haven't measurement them personally. However, > that isn't what is usually claimed. What is usually claimed? For sure, a DI system will output a higher voltage when the demand is there, but firing voltages and spark line voltages are measurably lower. >In any event, the strength of the > spark is not a huge factor in starting the car in cold weather. Thank you. That is what I've been saying all along. >I proper fuel/air mixture will ignite with only a small amount of > provocation. Correct. The majority of the heat that ignites the mixture comes from compression, the last 5-10% comes from the spark across the spark plug gap. Ooops, I did it again, I threw out a number that I can't provide verification for yet is standard teaching. > The really strong spark is needed in cases where the ratio > isn't ideal. That is why I can believe that the ignition system on a > non-FI car might need to be more robust as it is much harder to ignite a > mixture that isn't ideal. A lean mixture is harder to light than a rich mixture, so it all depends on what exactly is keeping the cold engine from wanting to run, but for carbureted vehicles it usually amounted to gasoline washout inside the cylinder, the washout occurs because the old choke systems were very poor at controlling the amount of fuel they delivered. > > The greatest gap theory was authored by Mac VandenBrink in 1965, > > Mac worked as an EE for many years for Allen Test Products. [quoted text clipped - 9 lines] > somebody else somewhere would have researched or commented on it. Thus > far I've found zilch. I don't know, it isn't like the "greatest gap theory" has been on the front burner technology wise like putting a man on Mars might be. I can tell you that on i-ATN, Mac writes that he was scoffed at over his theory, one of his college professors attended one of his classes, this professor had authored some books on EE, the professor told Mac after the class that contained discussion on greatest gap that had he taken Mac's class before he had authored some books, the content of those books would be different in that regard. His theory is very easy to prove in person with the correct equipment, connect an engine analyzer and set it to measure secondary ignition voltage, using insulated pliers, remove a spark plug wire from the spark plug (engine running of course) and observe the firing voltage, the firing voltage will not increase even though you can hear the arcing until the gap you're creating exceeds the value of the spark plug. The other observation one can make is to perform this same exercise on a DI equipped vehicle with an engine analyzer capable of measuring firing voltage during the waste spark event, the voltage on waste spark will begin to increase before the voltage for compression spark will increase. Now, not that what I'm saying gets confused, the rotor air gap is not always the dominant (greatest) gap, but during cranking on a cold engine with a carburetor with very little throttle opening, the choke closed and very little pressure being developed in the cylinder, the rotor air gap probably will exceed the value over the spark plug gap. Lots of different things in play here... Bottom line, DI systems are utilized because they have many fewer parts and because splitting the ignition load amongst multiple coils increases the working life of those coils, not because there is some requirement for lightning bolts to get a cold engine running. >>I don't see how. The voltage output of the coil is a direct function of >>the strength of the field around the coil that is collapsing. The [quoted text clipped - 17 lines] > and it's pretty much dead nuts on, probably because the > dielectric of the air gap is pretty predictable. Using an air gap to measure voltage isn't the same thing at all as claiming that an air gap will CREATE a higher voltage. I agree completely that an adjustable air gap can be used to measure the potential available between two points, in this case the secondary coil and ground. That is pretty basic physics. What I don't believe is that making a gap larger will INCREASE the voltage available from the coil. I maintain that the coil has a certain voltage capability and the size of the gap you put in series with the secondary doesn't change that one whit. If the gap is small enough so that the voltage available will ionize the air in the gap, then a spark will occur. If the gap is larger than what the available voltage can span, then no spark will occur. But making the gap wider doesn't make the voltage higher. At last I've seen no theory or evidence that this is the case. Matt > >>I don't see how. The voltage output of the coil is a direct function of > >>the strength of the field around the coil that is collapsing. The [quoted text clipped - 24 lines] > and ground. That is pretty basic physics. What I don't believe is that > making a gap larger will INCREASE the voltage available from the coil. It won't increase the total voltage available from the coil, if the coil has a maximum capability of 40 KV, then that is the most you will get. But looking at the spark tester, if a smaller gap represented where the number 20 is equals a coil output of 20KV and a larger gap where the number 40 is equals a coil output of 40KV, what other conclusion could be reached other than a larger gap will cause the circuit voltage to increase? > I maintain that the coil has a certain voltage capability and the size > of the gap you put in series with the secondary doesn't change that one [quoted text clipped - 3 lines] > occur. But making the gap wider doesn't make the voltage higher. At > last I've seen no theory or evidence that this is the case. I'm not talking about the total voltage capability, ignition coils do not normally run nor would you want them to run at there maximum total capability. If making the gap wider doesn't make the voltage higher, then please explain what value does need to change in a case such as a worn spark plug where the gap has increased because it sure as hell shows up as an increased voltage every time I've ever encountered it. >>>>I don't see how. The voltage output of the coil is a direct function of >>>>the strength of the field around the coil that is collapsing. The [quoted text clipped - 28 lines] > the coil has a maximum capability of 40 KV, then that is the most > you will get. That is my premise, but that isn't what has been claimed by a couple of others here. I'm not ruling out that this may even be possible, I just don't see how and haven't seen any theory that is supported by well-known laws of physics. > But looking at the spark tester, if a smaller gap represented > where the number 20 is equals a coil output of 20KV and a larger > gap where the number 40 is equals a coil output of 40KV, what > other conclusion could be reached other than a larger gap will > cause the circuit voltage to increase? No, the larger gap just shows that more voltage was available. It didn't change it. That is the same as looking at your outdoor thermometer when it is 80 out and then looking again and seeing that it is now down to 40 and claiming that your thermometer made it get colder out! :-) Measuring something and changing something are two different concepts. >>I maintain that the coil has a certain voltage capability and the size >>of the gap you put in series with the secondary doesn't change that one [quoted text clipped - 11 lines] > increased because it sure as hell shows up as an increased > voltage every time I've ever encountered it. How does a coil change its voltage capability? This is determined by the coil ratio and the voltage on the primary side. Are you saying that old cars with points ignition systems had a way to adaptively change the voltage being applied to the primary side of the coil? I don't think so. And you can't change the coil ratio so what else are you changing to affect the voltage at the secondary? Matt > > It won't increase the total voltage available from the coil, if > > the coil has a maximum capability of 40 KV, then that is the most [quoted text clipped - 4 lines] > don't see how and haven't seen any theory that is supported by > well-known laws of physics. Certainly not by me. > > But looking at the spark tester, if a smaller gap represented > > where the number 20 is equals a coil output of 20KV and a larger [quoted text clipped - 8 lines] > out! :-) Measuring something and changing something are two different > concepts. You either missed or are ignoring my previous comments where I stated that I had used this device while connected to my secondary ignition scope, when set to the 20KV gap, the coil output was 20KV, when set to the 40KV gap, the coil output was 40KV , that amounts to changing something and measuring the results. That is the result when you open the gap. > > I'm not talking about the total voltage capability, ignition > > coils do not normally run nor would you want them to run at there [quoted text clipped - 5 lines] > > How does a coil change its voltage capability? I never said it could. But they certainly do not output the same voltage under all operating conditions. Just like an engine does not produce the same horsepower under all conditions even though it may have a horsepower capability of 350 H.P. > This is determined by > the coil ratio and the voltage on the primary side. Are you saying that > old cars with points ignition systems had a way to adaptively change the > voltage being applied to the primary side of the coil? That would be one of the things one might observe a ballast resistor doing under various operating conditions although I'd maintain that it's actual purpose is to control current. > I don't think > so. And you can't change the coil ratio so what else are you changing > to affect the voltage at the secondary? The gap. It doesn't change the maximum voltage that an ignition coil can output but it (the gap) will change the voltage output up to the point where maximum voltage is achieved. Open the gap, it takes more voltage to arc across, cram more oxygen molecules in between the gap, and it will take more voltage to arc across the gap. Observe firing voltage at idle, let's say it's 12 KV, snap the throttle, the firing voltage increases to 22 KV, the reason it increased is because opening the throttle allowed more air molecules into the combustion chamber/in between the plug gap. When the engine decelerates, the firing voltage may drop to 4 KV. Secondary ignition voltage does not remain constant under various operating conditions. Observable fact, easily observable. > The rotor air gap increases firing voltage. > Comparing spark patterns on an ignition scope, the DIS voltages > (all else being equal) are lower, lower ionization voltage and > lower voltage across the plug gap compared to a distributor type > ignition system. But: 1. The voltage at the spark plug is limited by the breakdown voltage of the spark gap. Once you get a spark, the voltage required to achieve that is what you will measure. 2. Once you do get a spark, the total energy is what is really important. I don't know if you are measuring that in any way. > An old tow truck drivers trick when trying to start a stubborn > engine in the winter is to pull the coil wire slightly loose from > the distributor cap, this increases the voltage output from the > coil secondary (greatest gap theory). I have heard this -- even tried it once. But ask yourself, why don't they build (possibly additional) spark gaps into production ignition systems? I believe the air gap technique really serves as a band-aid for dirty systems: to explain, an air gap can cause a faster rise time of voltage. If the voltage rises slowly at the plug, energy can be lost through resistive (dirty) paths. I don't think a good system can be improved by a spark gap. Another thought: you guys are comparing early 80s carbs. These had all kinds of add-ons to cope with emissions regulations -- stuffing too much fuel down the exhaust does not help the cat. In my experience, earlier carbs with manual chokes work reliably -- providing the driver knows how to use them. > Now you're talking about vehicles that aren't properly maintained. So you are saying that well maintained US-built vehicles of the early '80 did not start well? Yet you (or rather Daniel) knock British cars (which I know from personal experiance start well in in damp and cold conditions provided they are well maintained). > > An old tow truck drivers trick when trying to start a stubborn engine > > in the winter is to pull the coil wire slightly loose from the [quoted text clipped - 3 lines] > I have heard this -- even tried it once. But ask yourself, why don't they > build (possibly additional) spark gaps into production ignition systems? They did. Called 'em "Series-gap spark plugs". All the major reputable makers made them, when there was a demand. > British cars (which I know from personal experiance start well in in > damp and cold conditions provided they are well maintained). WAAAAAhahahahahahaha! Sure, ace. \/\/hatever. Don't feel bad, just 'cause your country's automotive industry is an international laughingstock. In article <Pine.LNX.4.61.0501211640430.27351@localhost.localdomain>, > > The rotor air gap increases firing voltage. > > Comparing spark patterns on an ignition scope, the DIS voltages [quoted text clipped - 6 lines] > the spark gap. Once you get a spark, the voltage required to achieve that > is what you will measure. But the two voltages are different, it takes more voltage to jump the gap initially than it does to maintain it afterward. > 2. Once you do get a spark, the total energy is what is really important. > I don't know if you are measuring that in any way. More like energy over time, i.e., it is generally believed (taught) that a spark duration less than 1.5 milliseconds is an indication of a problem. 1.5ms on a breaker point system is not hard to achieve. > > An old tow truck drivers trick when trying to start a stubborn > > engine in the winter is to pull the coil wire slightly loose from [quoted text clipped - 3 lines] > I have heard this -- even tried it once. But ask yourself, why don't they > build (possibly additional) spark gaps into production ignition systems? Because it creates an enormous amount of electrical noise which tends to upset radio reception, drive the on board computers nuts and cause airliners to plummet to the ground. >I believe the air gap technique really serves as a band-aid >for dirty systems: to explain, an air gap can cause a faster > rise time of voltage. > If the voltage rises slowly at the plug, energy can be lost through > resistive (dirty) paths. I don't think a good system can be improved by a > spark gap. Yup, that's why the tow truck was summoned. > Another thought: you guys are comparing early 80s carbs. These had all > kinds of add-ons to cope with emissions regulations -- stuffing too much > fuel down the exhaust does not help the cat. In my experience, earlier > carbs with manual chokes work reliably -- providing the driver knows how > to use them. They will get the engine started, but drive off driveability still can not compare to modern EFI, especially PFI. > > Now you're talking about vehicles that aren't properly maintained. > > So you are saying that well maintained US-built vehicles of the early '80 > did not start well? Not compared to well maintained US built vehicles of the 90s with PFI > Yet you (or rather Daniel) knock British cars (which I > know from personal experiance start well in in damp and cold conditions > provided they are well maintained). Dunno, I've never owned a British car. I tried starting a Norton motorcycle once. I gave up. ;-) > Dunno, I've never owned a British car. I tried starting a Norton > motorcycle once. I gave up. ;-) It's always both amusing and sad to watch Brits stand there and insist their cars' electrical systems work. Only in England would they produce bike brakes that stop working when they get wet (and put Bobbies on them!), and car electrical systems that can't cope with more than 15% ambient humidity, let alone a drizzle... ...and then stand there and insist they're right and the rest of the world is wrong. Dan Stern wrote: >> Dunno, I've never owned a British car. I tried starting a Norton >> motorcycle once. I gave up. ;-) [quoted text clipped - 8 lines] >...and then stand there and insist they're right and the rest of the >world is wrong. Designed by: Sir John Lucas, original inventor of the concept of "Dark." God Bless, Dan'L ("If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around.") >>> Has anyone in the north country noticed that on very cold, below zero >>> F mornings almost every vehicle starts right up. Twenty years ago and [quoted text clipped - 18 lines] > distributors and hence the much improved insulation of the HT path from > the coil to the spark plugs. Nah, even the spark from a 60's era ignition is plenty to ignite and proper fuel mixture. Carbs just couldn't get it right in cold weather. A choke is a brute force way to try to get a combustible mixture at below zero temps. A computer controlled FI system can get it pretty nearly right every time. Matt |
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