94 Grand prix se stalls

toolmnator · #1 02-16-2009, 05:31 PM

I have a 94 Grand prix se, 3100 sfi, 190,000 miles.
The car quit on my daughter one night and has been in the garage since.
It will start just fine and run for 5 to 10 minutes than just die, some times
it will stumble a time or two in that short time but recover.
I have recently cleand the iac and install new fuel filter, crank sensor and
cam sensor, with each part it seems to run a little longer but still stalls,
There are no cel or ses lights.
I have not checked the fuel pressure, but each time I push the schrader
valve I get plenty of fuel,
Any input would be greatly appriciated.

CrazyHorst · #2 02-16-2009, 06:13 PM

I think based on above I'd have to recommend checking the fuel schraeder with a gage. The fuel pump is one that doesn't directly set a code as there is not a direct way to measure it.

The overall complexity of the PCM (and the resulting self-diagnostic capability) has improved over the years. 94 is on the early end of this curve IMHO.

tblake · #3 02-16-2009, 09:47 PM

Pull that darn Ignition Module off there and bring it to advance or autozone and have them test it for you. Have them do it over and over again to get her nice andf cooking. I have a feeling your ICM is flaking out on ya.

BTW, after it dies, are you able to restart it? If not, check for spark and fuel. What one are you missing?

toolmnator · #4 02-17-2009, 07:46 AM

Sorry........I left that one out, I did take the icm in and had it checked, They did it 3 times and said that was all that they could do, tested ok.........
Unfortunatley, I have spark and fuel........she starts right back up.
Any chance this could be an 02 sensor?

richtazz · #5 02-17-2009, 09:40 AM

You'll need to check fuel pressure. You can have fuel spray at the schrader valve without enough pressure to keep the car running. Your car requires a minimum of 41-47 psi, key on/engine off, and should drop 3-7 psi while running with the fuel pressure regulator vacuum line attached. If you have good fuel pressure, the next thing you need to check for is injector pulse using a noid light attached to each of the injector harnesses. No injector pulse would indicate a possible bad ECM, a pretty common problem on these cars due to it's being mounted under the hood and exposed to the elements.

toolmnator · #6 02-18-2009, 08:43 AM

Ok...did the fuel pressure test last night, key on 47 lbs...idleing 37 lbs, even when it stumbled held 37 lbs.
I don't have a noid light and don't know if I could get to the injectors..
I may pull the icm again and have someone else check it.
Thanks for the help.

richtazz · #7 02-18-2009, 03:25 PM

37 is on the low side while running, but taking into account a margin of error on the guage being used, is within spec. Double check the vacuum line going to the fuel pressure regulator for raw fuel. That would be an indicator that the diaphram is leaking and would cause stumbling/missing but not necessarily a low reading if it's a pin-hole.

Also, your car has 2 crank position sensors, one behind the harmonic balancer and one in the side of the block toward the firewall. Did you change only one, or both?

toolmnator · #8 02-18-2009, 06:03 PM

I have checked the vacuum line from the regulator, it's dry..no fuel.
I did not know that there are 2 crank sensors, I replaced the one on the side of the block, will look into that in more detail.
Thanks for the input.

toolmnator · #9 02-20-2009, 08:43 AM

Don't know if I have more than one issue here or not, but it is starting to look like a blown head gasket, smell of anti freeze, white smoke, lots of water comeing from tail pipe, had the radiator cap off, everytime the car would stumble it would purge anti freeze.
Had a scope on it that said water temp was 258, inside guage said about 160.
t-stat and ect check out ok.
Will keep updateting.

richtazz · #10 02-20-2009, 08:52 AM

that's bad news. I agree that it sounds like a head gasket to me as well. The dash guage runs off a separate sensor located in the rear cylinder head.

NOVAZ27 · #11 02-20-2009, 09:31 AM

HELLO. 190K on a 3100 series gm. My daughter's 96 Gran Am 3100 went only 120k before the coolant problem started. Her's never went into the cylinders but wound up in the crankcase. Messed up a bearing. easier to find another low milage engine. her's always used some oil & smelled of coolant. Turned out to be poor intake gaskets and internal dist. seal. She had the low mileage replacement engine upgraded with the better designed gaskets & seals + a new timing set. You might check your state to see if it pursuing the dexcool class action lawsuit. She may be entitled to some $$$$$. The state my daughter lives in is not a part of the lawsuit.

hope this helps

clutch492 · #12 02-06-2010, 01:16 AM

I am fairly sure that I know what is causing your problem. The anti-theft system. Your key has a resistor in it. That resistor has to stay in contact with the contacts in the tumbler. If it does not, the car will die. Then, you can restart it and drive a little ways and it will die again.

Here is what you do to fix this issue.

Measure the resistance of the key. To do this, check the resistance from one side of the resistor (small metal area on each side of the key) to the other side. There are 15 different resistances.

Now that you know the resistance, go to radio shack (The Shack) and buy a resistor of that value.

Now, below your steering column, there will be 2 very small wires. I believe they are white in color. these are the wires that lead to your key terminals. Cut them and solder in the resistor. You need to put the resistor on the car-side wires, not the wires that go up in the column. Start the car and drive on!

Easier fix would be to get a new tumbler and install it. This would require removing the steering wheel and a few other components. Not real difficult, except that the air bag needs to be taken loose. Be very careful and do not place the air bag anywhere that a static discharge can get to the connector.

By the way, I found this issue on a 1997 Lumina. Here is how I discovered what was causing it. It kept dying and I was seeing that it would die when I hit a bump on the road. So, I put it in the shop and decided to kick the front tire. AMAZING--- Every time I would kick the tire, the car would die. It was shaking the steering column enough that the key lost contact with the contacts in the tumbler. This is a true story!

So, when you go to buy a car, kicking the tires is not a bad idea. Ha Ha Ha

danman47 · #13 02-11-2010, 02:39 PM

Hello, i too have a 1994 GP 3.1, have changed the vss sensor as the speedometer was going crazy, also have the resistor fix in place, but i noticed this morning when i put my key in accessories and listened i heard no fuel pump noise, i then proceded to start car, out of the driveway and it died. I waited a min. then turned key to acces. and this time i heard fuel pump noise so i started car and it drove fine in to work. Just wondering if i now need to change fuel pump?

updated:1 day later car stalled on freeway, had to have it towed back to my place, now i do not hear fuel pump noise when i have the key in the accessories position, bad fuel pump, I guess, I will get new fuel pump and possibly a relay.

will post back

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