Car dies while running and won't start

[Godsend]

1993 Grand Am GT.
Let's get out of the way what the problem is...

I will be driving and the car will just die out almost like it is running out of gas but it has a full tank, sometimes it just starts to die and then will come back. Usually this happens when I am coasting or slowing down...

The other problem is when the car is hot and I shut it off for a while it won't start. The starter turns and the engine gets fuel but it wont get the last kick in the butt it needs to start. The only problem is that it isnt consistent. sometimes it will start right time after time after a whole of driving and other times i will drive down the road and it wont start.

Now what i have already tried and what I know...
New fuel pump, fuel filter, coil packs, ignition module (uder the coil packs), new plugs and wires, newer o2 sensor.

Maybe other things I can't jsut think of. Anyone else have this problem and know what fixes it? I can't tell if it getting power to the plugs and dont know how to test for that, also I have limited tools and resources :( College student.

[Godsend]

BTW I can hear the fuel pump running and there is pressure at the schroeder valve. (not sure if thats what I really mean but...)

It doesnt cough it just turns and cranks while i hold the key.

After a while it starts like nothing happened...

Checking air filter now will post if that is problem but not likely...

[doobiess]

ok having gas there dosent mean your pump is ok.. you need alot of pressure at that schrader valve for your engine to run right.. you should have like 35 psi at it.... its ok... check the fuel filter could be an obstruction in the line.... Also im just throwing ideas in the air... also a possibitly is the fuel pressure regulator... and check to make sure the vaccum connection to it is good.. and leaks or cracks...
Also are you getting any ECM codes....
but to me it sounds like your fuel pump... just putting out a little pressure but not what it needs for the car to run.... u need a fuel pressure tester or ... have it done in a shop for a few $ if you can get it there...

[doobiess]

Also does your car have the delco theft loc?

[Godsend]

hmm. Actually it just flashed a code today for the first time ever. Im amazed that it finally didi it. Should make figuring out whats going wrong much easier.

Not enough pressure sounds possible because sometime i can push the gas pedal and the car will rev up more but not enough to start or something...

Also, i dont know if this has anything to do with the current problem but when its running it idles really bouncy... The rpm's go up and down and rarely steady out. Also the battery meter was bouncing around the other day also... No enough alternator/battery power to sufficiently supply the pump on start-up, because the pump is new..

No theft lock...
I will have that code read tomarrow during the day and have a shop test it all out and post the result here. But Im not sure about the shop being to do anything because it is so interrmitent.

[Brad97GS]

You can test the code yourself for free (if you have a paperclip somewhere). I'll have to try and find the directions since your the second person I've mentioned this to lately. Maybe once I find the directions, I'll put a link to them in my sig. :) Anyway, sounds like it could be a bad crank position sensor, but that's just a guess. It could be many things.

Then again, if the voltmeter is not reading a steady output, perhaps your alternator is dying on you. Sometimes really weird things happen when alternators die.

[crashontome]

http://www.gaownersclub.com/forum/showthread.php?s=&threadid=100&highlight=paperclip

link to paperclip trick

[Brad97GS]

Ahh, thank you! I had actually forgotten to look...must be getting old! ;)

[Godsend]

I have the codes they are 21 and 27

21: Throttle Position sensor TPS or circuit- voltage high.
27: Quad driver module circuit.

[Brad97GS]

Those codes have to do with the TPS (Throttle Position Sensor) and the 3rd gear switch. Seems odd that these sensors would have anything to do with the car stalling though.

You know, after reading your first post over again, I wonder if you have a bad TCC solenoid. Those typically cause the car to stall after it's warmed up and slowing down off the highway. You can test that by unplugging the solenoid - the plug for it is on the front of the tranny. I don't know what the plug looks like on your car, but on my GA it was a round plug with 3 or 4 wires going into it. It was easier to get to if I removed the air intake tube. Doesn't explain the no start condition, but it may explain the stalling.

[Godsend]

From the Haynes repair manual.

The TPs section..
A broken or loose TPS can cause intermittent bursts of fuel from the injector and an unstable idle, because the ECM thinks the throttle is moving.


In the TCC section of the manual..
After the converter clutch applies, the ECM uses the information from the TPS to release the clutch when the car is accelerating or decelerating at a certain rate....

Another switch used in the TCC circuits is a brake switch, which opens the power supply to the TCC solenoid when the brake is applied.

A third gear switch is placed in series on the battery side of the TCC solenoid to prevent the TCC application until the transaxle is in third gear..

Now I can deduce from all the information that the solenoid may not engage when the car hits third gear or disengage when coming out of third gear which coupled with the pressure of the brake which may engage the the TCC that it can cause the car to stall out till i let off the brake or accelerate again??? What do you all think of that? My guess is that the solenoid needs to be replaced and the TPS also needs replacing?

[Godsend]

Originally posted by doobiess
... also a possibitly is the fuel pressure regulator... and check to make sure the vaccum connection to it is good.. and leaks or cracks...

Vacuum connections are all fine I just replaced all the vacuum hoses today. We'll see if the light still turns on soon...

[evilnissan]

I hate to beat the old thread but my Great Grandfather 93 Buick with the 3300V6 3speed trans is stalling comming up to stop lights after the car has been driven for a while.

My dad now has this car and *****es about it stalling out. So the last time I checked the codes it only came up with one for a quad-driver.


My real question is is I unplug the TCC (Torque converter lock up?) will it throw a check check engine light.???

[Brad97GS]

It might throw a check engine light - my '89 GA did when I pulled the plug. It is a good test at least. If he doesn't like the light being on all the time, he can have it fixed, but if he's like me and doesn't get bothered by the light, keeping the TCC solenoid unplugged is a good enough solution.