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Car Forum / Nissan / Nissan Maxima / June 2004

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Idles Rough

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Bruce - 23 May 2004 02:17 GMT
Hi,

This is my first time on this group...and I know it's for Maximas, but
perhaps my problem is generic enough that you may be able to help.  
Thanks.

I've got a 1997 Altima GXE with 65,000 miles. It's begun idling
very rough at 1000 rpm, and extremely rough at 750 rpm, where it
usually idles. I've replaced the easy stuff, cap, rotor, and plugs,
but the problem persists. I'm about to replace the fuel filter, but
I doubt that's the problem. I'm beginning to consider the fuel
injectors.

At $100 apiece, I'd like to first try to clean them. Is there an
additive, or a mechanical way to clean them? Or are the additives
just snake oil, and a temporary fix? Is mechanically cleaning them
something I should attempt myself, or best left to a shop?

My dad had his 1996 Maxima's injectors replaced ($1000) for rough
performance at all speeds, and sometimes non-starting, but it still
has the same problem, so I'm leary as to spending a lot only to find
that the injectors is not the problem in my Altima.

One other thing, the check engine light went on a few months ago.  The
car is driven very little.  Is there a way for me to find out the code
and what the code means?

Any other ideas as to what may be causing my rough idle at low rpm?
Other than that, the car runs fine.

Sincerely,
Bruce
Roger - 23 May 2004 06:11 GMT
You need to decide whether it is due to something not working right in the
engine which should cause decreased performance or if it's due to a bad
mount for the engine or trans.

> Hi,
>
[quoted text clipped - 28 lines]
> Sincerely,
> Bruce
Roger - 23 May 2004 06:15 GMT
If you think it's an injector issue, the engine would run REALLY rough if
one of them was not working. Best way to test for a failed injector is to
track it down to the cylinder by pulling off the ignition wires until you
hit one that causes no change.  If one of the injectors was bad the car
would run very bad.  You should try to pull the code to see what set off the
check engine light, (free at autozone).

> Hi,
>
[quoted text clipped - 28 lines]
> Sincerely,
> Bruce
Bruce - 23 May 2004 06:21 GMT
> If you think it's an injector issue, the engine would run REALLY rough
> if one of them was not working. Best way to test for a failed injector
[quoted text clipped - 35 lines]
>> Sincerely,
>> Bruce

Thanks for the reply.  I hadn't thought of a bad engine mount.  We don't
have Autozones here, but I will definitely track down the check engine
code.

Thanks again,
Bruce
BuddyWh - 23 May 2004 13:45 GMT
There are several good injector cleaners... many people (myself
included) have had very good results using Techron. It also works well
with combustion chamber and valve deposits, and is recommended by BMW.

While it's most effectively used periodically to remove light deposits
and varnish build-up, before it becomes a problem, you could try this:
add two bottles to a full tank and burn off that tank, then run one
bottle in the next tank.  I had good luck doing this on my Rodeo when
I had rough idle and weak low end at about 80K miles, and I've read
where several others have too. Even if it doesn't solve the problem,
it does no harm and is not very expensive before going on to other,
more expensive remedies.  

There are some shops that use special equipment to run cleaning
solvents through the fuel rail and injectors while still on the car.
That can be effective, but serious contamination means you'll need a
true injector cleaning.  This means removing the ejectors from the
engine and  cleaning them in fairly strong solvent, using pressure and
ultrasonic baths, then checking the spray pattern and flow.  I'd try
to get a shop to do this before I'd consider the expense of
replacement.

These aren't just snake-oil... they really are effective within each
remedy's abilities.  But if the problem is mechanical or electrical
then any kind of cleaning will do nothing.  

BuddyWh

>Hi,
>
[quoted text clipped - 28 lines]
>Sincerely,
>Bruce
Bruce - 23 May 2004 20:32 GMT
Hi,

I really appreciate your thorough response about fuel injectors.  I'm
from the (really) old school of carburetors, and am not familiar with
fuel injectors.  I did some reading on them yesterday, though, so I'm
learning more, a little at a time.  I should educate myself on them, as
all my cars now have fuel injectors.

I took the car out this morning, and except for the rough idle, it ran
just fine.  Sometimes the idle stays above 1000 rpm, and sometimes it
drops to about 750 rpm.  If the idle stays above 1000 rpm it's fine, but
when it drops below that, it's rough, hot or cold.  I'm going to look at
the specs. and see what idle should be.  Perhaps it's supposed to be 1000
rpm, and is dropping for some reason.  The problem is that I never drive
the car, so I don't know what's 'normal'.  My daughter drives it
primarily on very short trips to school and it never warms up.  I tend to
feel and hear developing problems before anyone else, but with the girls
in my family, I'm usually informed about a problem after it's been around
for a while.  Not complaining, just stating the dynamics at my house.

Thanks to Roger's advice, I did locate an Autozone in my area, where they
USED to test diagnostic trouble codes for free.  Now, the state of
California, and only the state of California, forbids them to do this for
free.  So, they don't even do it for a charge, but they will loan you the
equipment for a deposit of $180 (it's $90 to buy it outright).  I
borrowed it, and asked for some advice on it's use, but they said they
weren't even allowed to give advice.  However, the fellow was nice enough
to break that law for me. <g>

Hope the California legislature doesn't find out that I got some free
advice.  Sorry, but I feel a rant coming on about our lawmakers.

I'm going to check the diagnostics codes and go from there.

Thanks again,
Bruce

> There are several good injector cleaners... many people (myself
> included) have had very good results using Techron. It also works well
[quoted text clipped - 56 lines]
>>Sincerely,
>>Bruce
Bruce - 23 May 2004 23:48 GMT
> Hi,
>
[quoted text clipped - 7 lines]
> but the problem persists.
>BIG SNIP

> One other thing, the check engine light went on a few months ago.  The
> car is driven very little.  Is there a way for me to find out the code
> and what the code means?

OK, I borrowed an Actron ODB II Auto Scanner, model CP9135, to see what
made the check engine light come on.  I get code P0304, with the
description Cylinder 4 Misfire Detected.  All other systems, fuel, O2,
etc, tested fine.

Hoping that this would be a simple ignition wire problem, I bench tested
the number 4 wire, and it is fine.  I tested all other wires to be sure
my testing method was ok, and they also tested fine.

I put the wires back on, and then pulled number 4 from the plug head, and
held it close to the valve cover.  A very consistent and steady spark
jumped to the valve cover, and there was no noticeable difference as to
engine idle.  In other words, the car did not idle any rougher with the
number 4 disconnected.

I am now stumped.  With a number 4 cylinder misfire detected, I expected
the plug wire to be bad, yet a steady spark jumped from the wire's end to
the ground (valve cover).  I can't swap wires between plugs to test,
because the numbe 4 wire is the shortest wire, and won't reach any other
plug.  

Also, why is it that with a steady spark observed, there's no difference
whether the plug wire is or is not connected to the plug?  If I'm getting
a steady spark, what else could be causing a misfire?  Not timing, since
the other 3 plugs are firing fine.  Not a fuel problem, because the
scanner detected none, and the plug would fire anyway, fuel problem or
not.

I'm really at a loss at this point, and I hate to turn the thing over to
a shop at this time.  I'll have to think about this some more, and hope
that someone may have an idea.

Sincerely,
Bruce
Bruce - 23 May 2004 23:59 GMT
>> Hi,
>>
[quoted text clipped - 46 lines]
> Sincerely,
> Bruce

I did some googling.  See this:

http://www.alldata.com/service_provider/techrx/2002/200201212b.html
E. Meyer - 24 May 2004 01:10 GMT
On 5/23/04 5:48 PM, in article
Xns94F2A0D57A51Cparcxmannetscapenet@204.127.204.17, "Bruce"
<parcxman@netscape.net> wrote:

>> Hi,
>>
[quoted text clipped - 39 lines]
> scanner detected none, and the plug would fire anyway, fuel problem or
> not.

If there's no difference with the plug connected or not, and there is spark,
then the only other two choices are no fuel or no air for combustion.  It
sounds like a stuck injector on that cylinder (no fuel getting in).

> I'm really at a loss at this point, and I hate to turn the thing over to
> a shop at this time.  I'll have to think about this some more, and hope
> that someone may have an idea.
>
> Sincerely,
> Bruce
Bruce - 24 May 2004 01:31 GMT
Yes, it sure does sound like either no air or fuel, since there is spark.  
What's got me is there is a check on the scanner for fuel system, and it
checks out ok.

I'm now checking this:

http://www.alldata.com/service_provider/techrx/2002/200201212b.html

which is consisent with code P0304, Cylinder 4 Misfire Detected.

Thanks for the reply,
Bruce

> If there's no difference with the plug connected or not, and there is
> spark, then the only other two choices are no fuel or no air for
[quoted text clipped - 7 lines]
>> Sincerely,
>> Bruce
NissTech - 24 May 2004 02:36 GMT
Awww C'mon guy's .

Y'all are better that this.

This is guy has provided everything you need to diagnose his problem.

Stay tuned kiddies.

Will the mighty Bruce get the assistance he needs........ maybe ?

Will BuddyWh be able to figure it out, so far he is as cold as ice with his
dirty injector theory....maybe not

Tune in next time...

Same Bat time... Same Bat channel

> Yes, it sure does sound like either no air or fuel, since there is spark.
> What's got me is there is a check on the scanner for fuel system, and it
[quoted text clipped - 20 lines]
> >> Sincerely,
> >> Bruce
Steve T - 24 May 2004 04:38 GMT
> Awww C'mon guy's .

What?

There can't be anything wrong with the car, the computer/scan tool says
it's all OK!  :-)

Signature


Steve

http://www.atlantaracing.com

BuddyWh - 27 May 2004 01:30 GMT
>Awww C'mon guy's .
>
[quoted text clipped - 8 lines]
>Will BuddyWh be able to figure it out, so far he is as cold as ice with his
>dirty injector theory....maybe not

Actually... I never offered any diagnostic theories as to what his
problem could be... I was just answering his question about injector
cleaning.  I'm as curious as anyone as to what could be wrong....

let's see....  fuel... spark.... timing... compression  hmmmm

>Tune in next time...
>
[quoted text clipped - 24 lines]
>> >> Sincerely,
>> >> Bruce
Steve T - 24 May 2004 04:36 GMT
.

> Also, why is it that with a steady spark observed, there's no difference
> whether the plug wire is or is not connected to the plug?  If I'm getting
> a steady spark, what else could be causing a misfire?  Not timing, since
> the other 3 plugs are firing fine.  Not a fuel problem, because the
> scanner detected none, and the plug would fire anyway, fuel problem or
> not.

A scanner can't tell if there is a mechanical problem with an injector. I've
seen many cars that run like crap but the computer says everything is OK.
Have you pulled the plugs yet? Does it have NGK plugs or something else?
Signature


Steve

http://www.atlantaracing.com

Bruce - 24 May 2004 06:55 GMT
> .
>>
[quoted text clipped - 9 lines]
> everything is OK. Have you pulled the plugs yet? Does it have NGK
> plugs or something else?

Hi, Steve...I like your sense of humor.

Yes, I have pulled the plugs and they were worn normally.  The gaps were
huge since the electrodes were worn.  I did replace them, with the proper
NGKs and gapped per the owner's manual.  

I did check all spark plug holes for water, and there is none. I could
also see all the piston heads, and they all looked the same.  I also
pulled all plugs, one at a time, and turned the engine over and then
smelled for gas to see if there was any difference in smell.  I was
smelling to see if gas was getting to number 4, but not being burned.  
All smelled the same.  I'm not sure what this told me, though.  I
exptected to smell gas in number 4.

Here's something I did try:

Remember that number 4 is misfiring.  The scanner indicates this (yeah, I
know the scanner can't diagnose a mechanical problem like a sticky
injector, as you say) and when I pull the number 4 ignition wire off
while the car is idling, there's no difference in idle.  Also let it be
known that since the number 4 wire is the shortest of the bunch, I can't
just swap it with another, so I pulled number 3 off and put it on the
number 4.  Yes, I did connect the wires correctly, observing firing
order.  I started the car.  Now I've got no number 3, so it's idling
rough, but I've got a wire going to number 4.  This may be the
hint...when I pulled off the good number 3 wire that was connected to the
number 4 plug, the idle got worse.  This indicates, at least to me, that
the number 4 wire is bad, even though it tests good for continuity and
resistance.

The next step is to install a new set of ingition wires.  They're $50 at
Autozone.  This seems like the next cheapest step in the elimination
process.  I'll do this tomorrow, unless someone has another idea.

By the way, I kind of like that scanner.  I looked at some other, more
expensive ones.  Neat little toy.  While I still have it, I may check my
other cars, all of which are running fine.  But, it may be like going in
for a check up when you feel good...the doctor finds some little thing
and wants you back for more tests.  Hmmm...maybe I won't test the other
cars.

I'll keep you posted.

Sincerely,
Bruce
Steve T - 24 May 2004 15:47 GMT
>  This indicates, at least to me, that
> the number 4 wire is bad, even though it tests good for continuity and
> resistance.

You probably missed where it's burned through the side..
Signature


Steve

http://www.atlantaracing.com

Bruce - 25 May 2004 07:44 GMT
>>  This indicates, at least to me, that
>> the number 4 wire is bad, even though it tests good for continuity and
>> resistance.
>
> You probably missed where it's burned through the side..

Crap.  I replaced the ignition wires and problem persists.  Hmmm...

Time for the Techron?  I bought two bottles and I'm ready to pour it in.  
Yes?  No?

Bruce
Steve T - 25 May 2004 08:06 GMT
>>>  This indicates, at least to me, that
>>> the number 4 wire is bad, even though it tests good for continuity and
[quoted text clipped - 6 lines]
> Time for the Techron?  I bought two bottles and I'm ready to pour it in.
> Yes?  No?

 Now you're just guessing, just like I am but you're looking at the car!
Have you checked for vaccum leaks? I doubt pour in the tank FI cleaner will
fix it if it is an injector. Is that injector even clicking etc etc.

Signature


Steve

http://www.atlantaracing.com

NissTech - 25 May 2004 23:31 GMT
Good Job Steve !!!

> >>>  This indicates, at least to me, that
> >>> the number 4 wire is bad, even though it tests good for continuity and
[quoted text clipped - 10 lines]
> Have you checked for vaccum leaks? I doubt pour in the tank FI cleaner will
> fix it if it is an injector. Is that injector even clicking etc etc.
JM - 24 May 2004 21:50 GMT
It may not be your biggest problem, but if you haven't replaced the
PCV valve, do so.  It can result in a bad idle.

JM
NissTech - 24 May 2004 23:18 GMT
Ok Gang.

Here is your hint , It is 3 words long .

Lean Cylinder Missfire.

Hmmmm, Now you have to ask yourself .... Self, What causes a lean cylinder
missfire?

Homework Assignment,
due May 25 . 7p.m EST

What can cause a lean cylinder missfire ?

Steve T , sorry dude you are exempt from this test but feel free to answer
it anyway.

Will all the brainiacks on alt.autos.maxima be able to figure out this
runability condition?

Will Commissioner Gordon be able to find the Bat signal in time.

Tune in tomorrow.....
Same Bat Time...... Same Bat Channel

> Hi,
>
[quoted text clipped - 28 lines]
> Sincerely,
> Bruce
Bruce - 25 May 2004 07:47 GMT
> Ok Gang.
>
[quoted text clipped - 20 lines]
> Tune in tomorrow.....
> Same Bat Time...... Same Bat Channel

BIFF!  BAM! SPLAT!  ZOWIE!
Bruce - 25 May 2004 08:16 GMT
I'll take a crack at it.  Not enough fuel caused by a clogged injector?

Bruce

> Ok Gang.
>
[quoted text clipped - 53 lines]
>> Sincerely,
>> Bruce
Dan - 25 May 2004 21:29 GMT
> Ok Gang.
>
[quoted text clipped - 53 lines]
>>Sincerely,
>>Bruce

Oooh...A test!  My guess would be either a bad injector or
an injector wiring/harness connection problem.  If you do
the ol' "screwdriver to the ear" trick does the injector on
that cylinder make the typical clicking noise at idle?
NissTech - 25 May 2004 23:30 GMT
Ok Class,

I know it is not 7 p.m EST but my Tampa Bay Lightning are in the Stanley Cup
Finals and game 1 is tonight.

Ok here goes.

Things that can cause a lean cylinder missfire

A clogged/non working injector would definitely cause it , but it is not the
case with this car.

Good answer by the way, at least you are thinking about it.

Think about this for a moment

What else can cause it .....

Lets define a lean cylinder missfire.

when the mixture of air versus fuel to a particular cylinder becomes
unbalanced (more air than fuel) when the spark plug goes to ignite the
mixture there is nothing to burn, the over abundance of air and depleted the
fuel charge so there is no burn, hence the missfire.

so , one would next investigate a vacuum leak to that particular cylinder.

So think about this one for a while and I will check back late in the 3rd
period of the hockey game

Go BOLTS !!!

> > Ok Gang.
> >
[quoted text clipped - 58 lines]
> the ol' "screwdriver to the ear" trick does the injector on
> that cylinder make the typical clicking noise at idle?
Ttime - 25 May 2004 21:42 GMT
I have a 95 Maxima and recently got a tune up just because it was time.
The next day the car started running rough so I took it back to Pep Boys
where I got the tune up and they saw nothing wrong. The condition has
worsened so I took it back to Pep Boys Saturday.  They checked the spark
plugs and they were fine and did a diagnostic and there are no codes
coming up, but they know it is something misfiring with the injection
system.  They said they cannot do individual tests on the 6 injectors and
I would need to take it somewhere else.  What should I do next.  Any help
is greatly apreciated.  
Steve T - 26 May 2004 02:57 GMT
> I have a 95 Maxima and recently got a tune up just because it was time.
> The next day the car started running rough so I took it back to Pep Boys
[quoted text clipped - 4 lines]
> system.  They said they cannot do individual tests on the 6 injectors and
> I would need to take it somewhere else.  What should I do next.

Better question what should you have done first? NEVER take a car to pepboys
for service!

My guess? They used bosch platinum plugs which are useless junk..

Signature


Steve

http://www.atlantaracing.com

Ttime - 26 May 2004 04:59 GMT
I should have mentioned that I am no mechanic AT ALL, so excuse me for
going to a chain type of repair shop that I thought was decent.  I am on
this site for genuine help, not for criticism of where I have taken the
car or the type of car knowledge I should of been born with.  Moving
along... they checked the spark plugs and they are fine and I saw them
check them, so to repeat myself, what should I do next??  I am a mother of
three boys and would like to know how I can fix this myself if possible.
Thanks to those who want to help and maybe I won't go to Pep Boys again,
so thanks for that advice.
Steve T - 26 May 2004 06:41 GMT
> I should have mentioned that I am no mechanic AT ALL, so excuse me for
> going to a chain type of repair shop that I thought was decent.  I am on
> this site for genuine help, not for criticism of where I have taken the
> car or the type of car knowledge I should of been born with.

Chill out, I WAS trying to advise you on the mistake you made, sorry if you
can't take it the way it was meant.. We have cars that drove into those
places -towed- to our shop because they killed them and can't even get them
running to drive out under their own power! The tire stores are just as
bad.

> Moving
> along... they checked the spark plugs and they are fine and I saw them
> check them, so to repeat myself, what should I do next??

Again what kind of plugs did they use? Maybe to the untrained eye they "look
fine" but given the car was fine before they did this work, more than
likely it has something to do with the VERY poor quality parts they sell
and use. How do "they know it's misfiring due to the injection" yet don't
have a clue as to what it is? This is the line they use to shift blame from
themselves. They "don't do fuel injection work" so everytime they screw a
car up, this is the line they are taught at training school to tell
customers. You'll probably never get anywhere with these people, best bet
is to find a shop that specialises in nissans and get them to look at it.
The money you spent at pepboys was a waste.

Signature


Steve

http://www.atlantaracing.com

JM - 26 May 2004 20:26 GMT
> I should have mentioned that I am no mechanic AT ALL, so excuse me for
> going to a chain type of repair shop that I thought was decent.  I am on
[quoted text clipped - 5 lines]
> Thanks to those who want to help and maybe I won't go to Pep Boys again,
> so thanks for that advice.

Take the car to a Nissan dealer or Japanese specialty shop, and get
them to figure out what's wrong.  Or, it may be cost effective to just
have them do a second tuneup instead of high-priced diagnostic time.
(Someone will probably flame me for this bit of advice.  It's a gamble
either way.)

If it is traceable to something Pep Boys did, then contact Pep Boys'
manager and tell him you want a refund or will dispute the charge.
(You did charge it, didn't you?  It's the only meaningful protection
that you have.)

If they won't take off the charge, then follow up with your credit
card company immediately.  Send them a dispute, IN WRITING, include
the second repair bill, and any written statement that you can wrangle
from the second shop as to the problem.  (It is probably also best to
use the same charge card you used at the first shop.)

At least take some delight in the fact that your card company will
charge Pep Boys about $25 just to review the dispute with them,
whether or not it is taken off your card.

I used to work at Sears automotive department while in school.  All
these shops are into selling frequently questionable parts, and have
just enough skill to slap them into the car.

JM
Ttime - 26 May 2004 05:09 GMT
I should have mentioned that I am no mechanic AT ALL, so excuse me for
going to a chain type of repair shop that I thought was decent.  I am on
this site for genuine help, not for criticism of where I have taken the
car or the type of car knowledge I should of been born with.  Moving
along... they checked the spark plugs and they are fine and I saw them
check them, so to repeat myself, what should I do next??  I am a mother of
three boys and would like to know how I can fix this myself if possible.
Thanks to those who want to help and maybe I won't go to Pep Boys again,
so thanks for that advice.
NissTech - 26 May 2004 23:52 GMT
Aww .. C'mon guys you don't want me to just give you the answer do you ?

That is too easy, besides you won't learn anything

Clue :

Massive Vacuum Leak @  number  4 cylinder ONLY !

> Hi,
>
[quoted text clipped - 28 lines]
> Sincerely,
> Bruce
Bruce - 27 May 2004 01:39 GMT
Ah, don't take the fun away. <g> I was about to check around cylinder
number 4 tonight and report back.  I think it's a good HINT.

Been busy with computers, kids, etc at home...and haven't been able to
write back from work as our news server is down (I don't care for the
google news as it's incomplete).

Bruce

"NissTech" <Haywood_Jablowme@msn.com> wrote in news:Xc9tc.29434$Ol3.19796
@twister.tampabay.rr.com:

> Aww .. C'mon guys you don't want me to just give you the answer do you ?
>
[quoted text clipped - 36 lines]
>> Sincerely,
>> Bruce
BuddyWh - 27 May 2004 01:45 GMT
>Aww .. C'mon guys you don't want me to just give you the answer do you ?
>
[quoted text clipped - 3 lines]
>
>Massive Vacuum Leak @  number  4 cylinder ONLY !

Interesting...  I've had some experience chasing down disconnected
vacuum lines on my older cars to clear up bad idle.  But how does this
explain the detected misfire?  This really is a question... I wonder
how the computer would detect a misfire at  #4 if it isn't due to
something electrical.

>> Hi,
>>
[quoted text clipped - 28 lines]
>> Sincerely,
>> Bruce
NissTech - 27 May 2004 02:12 GMT
Ok Bruce I won't give you the answer just yet.

Tricks to finding vacuum leaks.

Use a mildly combustible spray (like carb cleaner) around the effected area
when the engine is running, if the idle smoothes out you have found your
leak.

I expect your diagnosis by Friday evening :-))

> >Aww .. C'mon guys you don't want me to just give you the answer do you ?
> >
[quoted text clipped - 42 lines]
> >> Sincerely,
> >> Bruce
JM - 28 May 2004 06:08 GMT
An EGR valve that's stuck open at idle can have the same effect as a
vacuum leak. So too can the wrong PCV valve (one that flows too much
air for the application), or a loose PCV hose. The rough idle in these
cases is caused by "lean misfire." The fuel mixture is too lean to
ignite reliably so it often misfires and fails to ignite at all. Lean
misfire will show up as elevated hydrocarbon (HC) readings in the
exhaust—enough, in fact, to cause a vehicle to fail an emissions test.

Lots of info on lean misfires (including the above quote) at:

http://members.aol.com/carleyware/library/vacleak.htm

JM
Steve T - 28 May 2004 06:57 GMT
> So too can the wrong PCV valve (one that flows too much
> air for the application),

I'm not so sure about that one on a FI car. This extra air is still going
through the MAS so the computer would add fuel for this air. It's just
bypassing the throttle plate via the crankcase. For it to lean out the
engine, it has to be air that never passes over the MAS. Plus most cars
have a centrally located PCV valve so even a broken hose isn't likely to
-kill- one cylinder like the OP stated, nor would EGR for the same reason,
it would just polute the whole engine with exhaust, not one cylinder.

Now a brake booster is another story. Most of them do attach to the intake
near one hole and a leaking booster can cause a cylinder or two to go dead
at idle when the brakes are applied.

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Steve

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JM - 28 May 2004 17:24 GMT
> I'm not so sure about that one on a FI car. This extra air is still going
> through the MAS so the computer would add fuel for this air. It's just
[quoted text clipped - 7 lines]
> near one hole and a leaking booster can cause a cylinder or two to go dead
> at idle when the brakes are applied.

That sounds like a good analysis to me.  So we're left with, what?
Leaking gasket, or injector o-ring?

JM
Steve T - 29 May 2004 01:02 GMT
>> I'm not so sure about that one on a FI car. This extra air is still going
>> through the MAS so the computer would add fuel for this air. It's just
[quoted text clipped - 11 lines]
> That sounds like a good analysis to me.  So we're left with, what?
> Leaking gasket, or injector o-ring?

 Vac hose that goes near that cylinder or as I said a bad booster. Could be
a blown out intake gasket, some nissans have been bad about that in the
past. Might be a dead injector or as you said an injector seal? Who knows!

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NissTech - 29 May 2004 02:53 GMT
The answer is here , Steve T hit it on the head .

A leaking intake manifold gasket, a common occurrence on the Altima

> >> I'm not so sure about that one on a FI car. This extra air is still going
> >> through the MAS so the computer would add fuel for this air. It's just
[quoted text clipped - 15 lines]
> a blown out intake gasket, some nissans have been bad about that in the
> past. Might be a dead injector or as you said an injector seal? Who knows!
Steve T - 29 May 2004 04:46 GMT
> The answer is here , Steve T hit it on the head .
>
> A leaking intake manifold gasket, a common occurrence on the Altima

I recall the old napZ engine did that quite a bit and would end up burning a
valve if the owner ignored it long enough. Seen any of the altimas do that?

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Bruce - 01 Jun 2004 14:52 GMT
> The answer is here , Steve T hit it on the head .
>
[quoted text clipped - 28 lines]
>> the past. Might be a dead injector or as you said an injector seal?
>> Who knows!

Been gone for the weekend; missed the Friday night deadline.

Well, I guess it could be worse, but it does seem like it's a leaky
manifold gasket around number 4.  When I spray carb cleaner around this
part of the intake manifold, the idle does smooth out, a very small
amount, but it is noticeable.  It's darn hard to get at this area, so
perhaps the leak is on the side of the intake port that I can't reach and
the fluid is being sucked around to there.  While sitting in the driver's
seat, the part of the port I can apply carb cleaner to is at 10 o'clock.

I've got the Haynes manual for the car, but this job looks like a
knuckle-bleeder.  I've got no idea how much it would cost to have it
done, so at this point I'm not sure what I'm going to do.

Luckily, my registration was due mid-May, which I've gotten, but a smog
check was not due this time around.

What to do, what to do...

Thanks so much to all that responded in this thread.  I'll be back.

Sincerely,
Bruce
Steve T - 02 Jun 2004 02:43 GMT
>> The answer is here , Steve T hit it on the head .
>>
[quoted text clipped - 41 lines]
> part of the intake manifold, the idle does smooth out, a very small
> amount, but it is noticeable.

Then you've found the problem...
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NissTech - 29 May 2004 00:50 GMT
Well Bruce

What is you Diagnosis ?

it is 7:49 p.m EST

I'll look again in another hour

> Hi,
>
[quoted text clipped - 28 lines]
> Sincerely,
> Bruce
 
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