 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Saab Cars / October 2006'93 9000 Aero misfire...
I have a'93 9000 Aero with about 130,000 miles on the clock. If I accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. This just happens for an instant and then it carries on accelerating hard as it should. I say 'misfire' because that's all I can think it is (maybe something else), but otherwise the car drives perfectly at all other times. Any ideas anyone? > I have a'93 9000 Aero with about 130,000 miles on the clock. If I > accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 3 lines] > but otherwise the car drives perfectly at all other times. > Any ideas anyone? Does your '93 have a distributor with a vacuum advance? It sounds like the timing is getting messed up at the point it needs to be advancing. Just guessing ... Paul Vart tog vägen vägen? SAAB : Nothing on earth comes close 93 9000's do not have a distributor. They have a DI cassette. No spark plug wires either. Charles > > I have a'93 9000 Aero with about 130,000 miles on the clock. If I > > accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 12 lines] > Vart tog vägen vägen? > SAAB : Nothing on earth comes close > 93 9000's do not have a distributor. They have a DI cassette. No spark > plug wires either. [quoted text clipped - 25 lines] >> Vart tog vägen vägen? >> SAAB : Nothing on earth comes close Could this be a turbo overpressurization with dumping thru the waste gate?? Sounds like a problem I had with my '93 Aero ... The 'Check Engine' light came on. So I checked it by turning the key in the ignition to the 'on' position (without starting the car). Sure enough, the light flashed three times indicating a faulty air temperature sensor, but then it flashed five times indicating a faulty throttle position sensor. So I left it for a while - and continued on my way down the parkway - when suddenly there was a 'jolt' or 'shudder' - quite violent. Almost as if the turbo was 'on' and 'off'. After that though, there was no turbo boost at all. In fact it behaved just like a normally aspirated car ... I replaced the APC solenoid (top of radiator - three hoses going into it) - as I was told it was this that was causing the 'misfire'. But, this didn't solve it. I checked the turbo wastegate actuator - but that looked fine. I checked the vacuum lines - but they looked fine also. So in desperation I took it to my local Saab garage where I was told that the diagnostic equipment couldn't communicate with the ECU and that I'd need a new one! (sod that I thought and left). So I limped back home and decided to check the spark plugs and DI cassette - and lo and behold there was a crack in the DI cassette. Now I don't know if this is what is causing the misfire - but I've ordered a new one - and will probably fit it this weekend along with new sparkplugs. I'll let you know if this cures my not-very-fast-anymore Aero ... (if it doesn't - I'll start looking for a second-hand ECU I suppose...) > > 93 9000's do not have a distributor. They have a DI cassette. No spark > > plug wires either. [quoted text clipped - 27 lines] > > Could this be a turbo overpressurization with dumping thru the waste gate?? Check your vacuum hoses - - from the fuel pressure regulator (little can about size of stack of quarters sitting on the passenger side end of the fuel rail feeding the injectors) vacuum line runs about 6" to the intake manifold. - from the charge air bypass control valve on the drivers side wheel well by the battery - 3 hoses run down behind the relay box by the battery and then - 1 branches off to the nipple on the 'hooter' and the other two run alongside the bottom of the batter - 1 to a 'wye' connector with a line feeding into the aquarium (and then into the dash for the boost gauge, I think) and one up to the underside of the throttle body (at least this is the setup on the electric throttle body for a '95 w/ TCS system) - from the boost pressure controller at the upper drivers side of the radiator, 3 lines - 1 to the turbo waste gate, 1 to the intake manifold and 1 to the turbo look at quasimotors site for photos that show the connections of the hoses to the BPC it could be other things, but the vacuum lines tend to rot in the engine compartment heat and are the easiest culprits to check and replace if they are all good - when was the last time the plugs were changed or re-gapped, was dielectric grease used to keep the spark from arcing down the plug insulators and and how's the direct ignition cassette doing? >I have a'93 9000 Aero with about 130,000 miles on the clock. If I >accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 3 lines] > else), but otherwise the car drives perfectly at all other times. > Any ideas anyone? > Check your vacuum hoses - > [quoted text clipped - 31 lines] >> else), but otherwise the car drives perfectly at all other times. >> Any ideas anyone? What about the DI cassette? > What about the DI cassette? The only way to see if it might be the cassette is to substitute another. One should always carry a spare in any case so it would not be a waste of money to buy an extra. > I have a'93 9000 Aero with about 130,000 miles on the clock. If I > accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 3 lines] > but otherwise the car drives perfectly at all other times. > Any ideas anyone? Maybe the ECU is cutting off the fuel in response to dangerously high boost pressure? John  SignaturePosted via a free Usenet account from http://www.teranews.com >> I have a'93 9000 Aero with about 130,000 miles on the clock. If I >> accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 8 lines] > > John When this happens it is like someone dropped an anchor out the back! It throws you forward into the seat belts, not what I would describe as a misfire. SignatureRichard Sutherland-Smith 19 Webb Road, Wanganui 4500 New Zealand > I have a'93 9000 Aero with about 130,000 miles on the clock. If I > accelerate hard the car seems to misfire violently at about 3500 - 4000rpm. [quoted text clipped - 3 lines] > but otherwise the car drives perfectly at all other times. > Any ideas anyone? Or is it the usual DI? Last about 60k miles, but is sensitive to overheating. If it's the DI going, the symptoms will worsen over a couple of weeks. it sounds to me like the engine is boost cutting, this happens when the boost pressure is to high the ecu closes the throttle for a split second causing a violent jult. I would try a new boost pressure control valve and check the air lines connected to it for leaks or splits. Good luck let me know how you get on. MTech > it sounds to me like the engine is boost cutting, this happens when the > boost pressure is to high the ecu closes the throttle for a split second > causing a violent jult. I would try a new boost pressure control valve and > check the air lines connected to it for leaks or splits. Good luck let me > know how you get on. MTech I did once have this problem on my 2.0 lpt, but not since i used higher octane fuel, e.g. Shell Optimax or V-Power as it's now called. I don't know what the V stands for, perhaps Vertical take-off?
|
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.