Problems

Kevlar

Kevlar

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Hi guys.

I also have a 96 Grand Am with the 3.1L. I've been experiencing something similar. Now, I recently had the head gaskets replaced by a reputable local shop where they also found and resolved some issues with the fuel evap system.

Not long after getting the car back, it started stalling at initial start up. The engine would start and run for a few seconds and then die as though running out of fuel. After a few more tries, the engine started and ran. When I'd rev it up it would sputter out like it had a rev limiter at around 3700 rpm. All this happens with no SES and no fault codes.

I initially thought that the fuel pump was fault and went to the cost and trouble of replacing that myself. After, it started more reliably but still sputtered out around 3700 rpm. Now it is stalling at start-up more consistently so, it's likely that replacing the fuel pump my have been a waste of time and money.

It was suggested to me by a helpful lady at O'Reilly's that it may be a faulty cam or crank sensor. I then sought out this place to see if there may be some further info here on the subject.

Also, I've found that if I spray engine starter fluid shots into the MAF body the engine will eventually continue to run on it's own.

If this rings any bells with any of you folks, I'd be interested in your kind suggestions. I will check the fuel pressure regulator as suggested above. Otherwise, I'll probably take it back to the mechanic that has been doing the work for me and see what he finds. If I find the fix there, I'll be sure to share it with you all.

Sorry for the long first post.
 
The mechanic may have left a vacuum line off or it failed due to being disturbed during the head work. The pressure regulator as you mentioned should be checked. The engine temperature sensor may be giving a faulty signal to the PCM. The IAC and throttle body maybe dirty and need cleaning.
 
I did check the pressure regulator, the vacuum line is nice and dry and pulls vacuum nearly enough to stick to my finger. I didn't measure the vacuum though.

If the engine temperature sensor sends a faulty signal to the pcm wouldn't there be a fault code or SES indication?

I'll have to check into cleaning the throttle body. I'm guessing there may already be a thread here with instructions to that end, I'll do a search but would appreciate also if someone can point me to it.

Thanks!
 
here is a video for cleaning the TB, yours maybe different. If the sensor is reading low it many not cause the PCM to throw a code just cause it to not correctly run the engine.

http://www.youtube.com/watch?v=41yFXjibtLY
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melsg5 said:
The mechanic may have left a vacuum line off or it failed due to being disturbed during the head work. The pressure regulator as you mentioned should be checked. The engine temperature sensor may be giving a faulty signal to the PCM. The IAC and throttle body maybe dirty and need cleaning.
Click to expand...
Well, I gave the throttle body a pretty good cleaning. It did start right up but stills sputters out around 3700 rpm so something else is the cause.

You mention the engine temp sensor, what would the symptoms be if it is giving faulty info?
 
Did you have this problem before the mechanic worked on the car? If not, is there a reason why you appear hesitant to just take it back to him? Is that 3,700 rpm when driving the car?
When you replaced the fuel pump, did you also replace the filter? Have you checked the fuel pressure with a gauge?
 
Well, I'm not sure if the problem existed before the majority of work was done, at that time, my wife was the principal driver. I just got her explanations of the car's misbehaving!

I'm also not sure if the engine stalls at 3700 under load, I haven't pressed it that hard. It does drive nicely under normal conditions when it runs.

I did replace the filter at the same time as the pump (I like Wix filters, by the way). I don't have the proper fitting size or adapter for my fuel gauge so I haven't checked the pressure at the rail.

The mechanic who's done the work is very good and I believe to be honest. If he finds the fault was his, I have no doubt that he will correct it at no cost to me. I have no hesitation in taking it back to him, I just thought I might find some answers here and save us both the trouble, not to mention cost should it turn out to be something new.

The other factor in not taking it in is, the mechanic has been out on vacation, returning tomorrow and I was hoping to resolve the issue this last weekend.

Ah well, so it goes, the plans of mice and men ....

I do appreciate your efforts, thank you.
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Alrighty then. This afternoon we picked up my daughter's Ranger from the mechanic and I asked him about my stalling problem. From my description, he went right to the IAC valve which melsg5 mentioned in his/her (no offense, I just don't know which) first post to me. He said sometimes it gets sticky and could cause the stall at start up.

He also told me that the rev limiting is normal in park and neutral and asked if it happens under load. I ran it up pretty good yesterday and learned that it will indeed rev just as high as I will foolishly allow under load.

So, I drove it home and pulled the IAC valve and gave it a good cleaning. Now I'll give it a few days trial period to see if that was ultimately the problem.

I'll be glad to have it fixed but kinda sucks in a way, after replacing the fuel pump at over $250.00 but that's what we get when we don't take the time to properly diagnose before going off, half cocked and replacing parts Willy-Nilly on assumptions! :rolleyes:

Stay tuned for summary or continuation ......
 
glad you hopefully got it resolved
 
Well. Time for an update. I decided today, to replace the IAC with new and when I started the engine, it fired right up. But then I turned it off and started it again to find that it stalled just as before.

This time though, I notice air noise as the engine stops. That shouldn't be. After a little investigation I find that the PVC tube has come loose near the connection to the upper intake plenum. Closer inspection reveals that the small tube that goes down to the evap. canister purge solenoid valve has broken off at the tee and someone repaired it by connecting the two ends with a rubber hose which has become hard and checked from the heat.

So the rubber hose had come off and I've got a great vacuum leak.

I removed the tube and found that the seal at the intake plenum is old, melted and has probably been leaking for some time. Wow. These little rubber parts are just not cut out to last 17 years I guess! :D

O'Reilly has a replacement for $9.00, it'll be here this Tuesday and I'll replace the PVC valve and grommet too while I'm there of course.

Hopefully this minor repairs will solve some of the pesky issues I've been having.

To be continued.........

:cool:
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Ok, it may be too soon, but I'm calling it. The car has started nicely every time it's been tried today. My wife drove it to work and back (70 mile round trip commute). I just went into the garage and started it twice. Very nice.

Amazing the problems a few vacuum leaks can make, and what a difference when they are fixed.

I think we'll keep it a while longer.

Thanks for the help Mel!
 
as long as the wife is happy all is well
 
Well, the problem popped up again. No idea what it is at this point. May be time to take it to the professional.
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Update.

After being parked in the garage for months I decided I needed to get off my duff and check it out again. I put the battery charger on this morning and let it get a nice charge all day long. Then I rented a fuel pressure gauge from O'Reilly today. I connected the gauge to the fuel rail and then cycled the pump with the ignition, the pressure came up nicely.

Then I started the car, it started normally and ran fine. The pressure read 38 at idle and would fluctuate from 36 to 42 when I revved the engine. So the pump seems to be working nicely. I disconnected the gauge and took it out for a drive to return the rented equipment, no problems.

Let it sit through dinner and a bit more then took it out again, still no problems and it's running well. I'll take it out again tomorrow and see if all is normal. I still don't know what the problem was(is?) I was thinking that maybe there was still some air in the fuel lines from the fuel pump change out but that should have self bled out by now.

Now, I checked again and when the car is in park, it will rev only to about 3800 rpm where it dies like it hits a limiter. When the car is in drive or any gear (forward at least, I'm not in the habit of flooring it when in reverse!) it will run strong up to near the red line so I'm thinking (hoping) there is a rev limiter programmed into the ECU. Can anyone confirm that?

Cheers!
 
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