91 firebird won start problem

I have a 91 firebird 3.1 v6. Ive had a problem where when i accelerate hard it would cut out and wouldnt come back until i let off the accelerator and pushed it down again or sometimes the car would just cut out and shut off when i floored it.So ive had this problem for about 5 months now and its been getting worse and worse until the other night when i was driving I accelerated and it died and when i started it back up it would idle but die as soon as i gave it gas even if it was in netrual.So i had it towed to goodyear and the next day they said it wouldnt start for them and they think the timing is off and it needs a new timing chain and it would be around 500 dollars.So i towed it back to my house to see if the problem might be something else before giving them 500 dollars to fix the timing chain.The car will crank but wont start. In the past month I have replaced the Spark plugs, spark plug wires, distributor cap, rotor, PCV valve, air filter, oil filter, transmission filter, fuel filter, fuel pump, fuel pump relay, throttle position sensor (TPS), Manifold Absolute Pressure Sensor (MAP sensor) and the Ignition coil.

If any one has any ides PLEASE HELP!

Hello there.
I have got more or less the same trouble and still seeking that information. Here is what I found over the net. there are 2 solutions, but i am not tested , yet:
Older Pontiacs stalling mystery SOLVED (Dante Estlin, 2004-05-20 14:50:36)
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I have a 1989 Pontiac Grand Am, Quad 4 motor, four door. It was given to me a couple of years ago 2002 by my father. Of course, being a guy in his 80s, he babied the car and as these older gents do, he bought a new car. I needed a car and took the Pontiac. It ran superb for two years. I even drove it to New York City from Buffalo 410 miles one way , drove it back and forth a number of times to Toronto 90 miles one way, and also used it every day the way Americans love to use their cars. Slowly, over time, I have been experiencing a stalling problem. Here\'s what happens. I drive the car for a few miles, maybe 5, maybe 10. Things are fine until something heats up, and if I have to slow down at a red light or stop sign, the car sputters and stalls. I could drive the car for 100 miles on a superhighway and have no problems, but once I have to deccellerate, it\'ll stall. The situation is worse in hotter weather. The car rarely stalls in colder weather. I love January. Anyway, after the car stalls and sits for anywhere from 7 to 17 minutes, it\'ll start right up and I can move along to my local destination. But it will eventually stall again as I deccelerate. If the car sits for an hour or so, I can drive further than if it sits for 10 minutes. I have done huge research on the problem. Huge. I\'ve taken it to mechanics. I\'ve had mechanics who won\'t work on it. Some think it might be a solenoid issue. I\'ve seen comments on myriad boards about others having this problem and it seems to be a mystery to most. The real tragedy is that GM has made a line of cars that have this problem. Anyway, after tons of research, here\'s the deal, and I hope this helps any of you out. The car is experiencing one of two serious problems. The first may be that a heat shield protecting fuel lines or filter may have shifted or broke or just eroded away, and this is causing fuel in the line to vaporize, thus causing the stalling. That\'s one theory, but I really don\'t ascribe to it. The theory I like is this: The car is having a serious Ignition Module IMfailure, which may also be linked to other electrical malfunctions. The IM needs to be replaced and you might want to replace, probably should replace, the Crank Sensor. The cost is steep. To drive it onto a Pontiac dealer lot is a minimum, no questions asked, $75.00 for one hour of mandatory diagnostics, even though you know it\'s an IM problem. The diagnostics could take two hours. Hopefully it won\'t take three. The mechanics will test every aspect - they have better equipment at dealers than do regular mechanics, and determine the exact point where fuel is not getting into the line and what is causing it it to choke or vaporize - certainly the IM. The cost of the Ignition Module is around $200. The crank sensor is around $30. So with one hour of diagnostics, and the parts, we\'re talking $305 without labor and any other parts. I hope this helps you out. As for me, I was just given, by a friend, a terrific 1993 Nissan Altima with 181,000 miles on it and it\'s good for another 75,000, I\'m sure. Oh, I know you\'re probably wondering, why do people keep giving this guy cars? I guess I\'m just a likable guy.
Re: Older Pontiacs stalling mystery SOLV (bigted, 2004-05-23 01:01:14)
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I had the same trouble with my 89 pontiac and GMC corsica ! there is a electrical plug on the transmition in most case if you look down between the radiator and the trans.. you will see iton the trans. ! just unplug it ! I was told that it has something to do with tork converter fill up when you are highway drive, and then when you slow down at a stop sign it will buck and stall ! then you can start it back up some time right away and you are one your way ! you will lose one of the top end highway gears ! but it will work fine . it is a 5 minute fix .I bought my pontiac knowing it was having this problem and got it cheap! when I got it home I unplugged it and its been 3yr. and still going I hope this is your problem ! not alot of mechanics know this !! good luck! BigTedI







stalling (dagan, 2004-04-02 20:17:43)
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i have cleand the carb..replaced all the vacum lines tried a new map sensor... haveing no trouble with the trans shifts fine ...would the tork converter do that stall at a stop? would the oxegen sensor do this? rins good other than that it will idel fine in park but put a load on it after it is warm then it will stall only after it is warm.anyone got an idea this is driveing me nuts
stalling (kyohty, 2004-04-16 19:53:07)
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hey i have a 91 trans am GTA and mine was doing about the same thing as yours i think. it would get warm and die when i stoped at a stop light and then pushed the gas again. It was the sensor in the engine block that senses how hot the engine is antifreeze temperature. it was reading the engine as cold at all times so when i would stop and push the gas again it would flood the engine with too much gas because it thought it was cold rather than a hot engine. but i dont know if you have the sensor because yours is carb. not tpi cause it is older so i dont know but i hope this helps. My temperature gauge in my car would read that it was operating under normal temperatures it worked it was just a bad sensor. Oh and if this doesnt apply to your problem im sorry i just thought it sounded like what i had. : Good Luck!
stalling (dagan, 2004-04-16 20:44:18)
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mine is throttel body injected
stalling (OATS, 2004-04-02 23:13:10)
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Make sure you list the fix, cause this will bug the hell out of me now. Oh, and I'm not possitive? I always thought the torque converter was activated as soon as you put the car in gear?
stalling (OATS, 2004-04-02 23:10:25)
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Normally you would be able to drive for short distance w/ a bad mass air flow sensor. I had one go on an old grand AM, and the car was just running like shit. But it is a possibility. They won't let you return it if its not the problem..... Shit, now this is pissing me off!
Re: stalling (grizz1975, 2004-05-02 15:13:06)
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my bet is the torqoc converter because that actds like the clutch when you stop if isn't working properly it would be like not pushing the clutch in on a manual

I do hope that it may help you.
Send mail if You are lucky.
Regards

Thanks for the reply Aigars i will try some of those. So far i have found out that it will start if i pour gas into the throttle body. I have checked the pump the fuel lines and the electrical cinnections to the injectors and they are all good.

Hi, t-bird.
My car is also at the electricians already 4 days. It's always difficult for them if the car has such symptoms from time to time. They checked transmission and found place for sensor. I have no answer yet for the coolant temperature sensor, but they will also go through all the wiring involved in engine work. Bad connection is more likely they said. Good luck :-)

Sorry I missed "found no sensor place at the transmission".

I have just put in a new Electronic Control Module (ECM) and changed the oxygen sensor and it still wont start, but i did time the car and the timing is correct so im pretty sure its not the timing chain like goodyear said. I also checked the fuel pressure and it is good.

Hi, t-bird.
I got back my car from electricians and didn't take money :-). They found nothing. And the car last 3 days runs perfect. What they did was checked some plugs (unplugged and plugged). I think that my problem is some kind of sensor giving information for the rate of revs - bad contact. Probably we have different troubles. I wish You good luck. If You fix Your problem pls let to know. I am going for vacations now till middle of July.

I had a similar problem with a tpi 350 and i found if you unplug the mass air flow sensor the ecm will bypass it. If the problem clears up then you know that is the problem. not sure if that applies to your motor but it is an easy thing to check. in case you are unsure it should be on your air intake. Good luck

Ok lets start with the basics yet once again- Do you have spark and fuel ?

If you dump fuel in the tbi it runs correct ? So you have spark but no gas - you have good fuel psi you said - sooo
Injector not working perhaps-- Shorted ?

Best way is get a Mitchell manual from the library and look at 'no start condidtion' you will go broke throwing parts at it...

Hi, t-bird.
My problem is solved. They found bad wiring connection at the alarm system. It is connected in some way with fuel pump and after a while contact was disappearing and pump stopped pumping lol. And I was close to change everything. That was my problem. Good luck.

My car is fixed. I took it to a mechanic and he replaced the ignition control module and changed the spark plugs and it started right up.He also said that the PROM in the ECM wasn't in all the way so that might have been the problem too.Thanks for all the suggestions though.

Fine, that our cars are OK now. Have a nice driving!
Aigars