Car dies after an hour!

[spyder2455]

As the title says, my car has been dying after about an hour of stop and go driving in warm weather. It always happens when I come to a stop and suddenly the idle will drop to around 600rpm and if I try and give it gas I can keep it running for a second, but eventually it will just die out no matter how far I push down the pedal. Once this happens, I attempt to start it by turning the key and pumping the gas pedal. Finally, after about a minute of cranking it over in traffic it will fire up and as long as I keep the rpms above 1500 I can get it home and out of the street. I have had this problem for as long as I can remember, and I have just been avoiding driving the car for too long. I have replaced the TFI module (about 6 months ago), distributor (after the stator went out), coil, fuel pump, fuel filter and pretty much every other sensor in the time I have owned the car. My thoughts still lean towards the TFI because this occurs when the car gets warm, however I have already replaced it twice. I plan on having the TFI checked tomorrow, but I need some ideas on what else could be causing this. If it happens to be the TFI, why would it go out so soon? Please help!!!

 

[HISSIN50]

Pull the diagnostics codes. A PIP is another option, and it often doesnt pop a code.

When it craps out, if you dont goose it, do you know if you have spark and injector pulsing? How is FP when it does this?

You have replaced the 3 biggies that I would normally think of, so more diagnostics might be revealing. When you have the TFI tested, be sure they do it repeatedly to heat it up.

Good luck.

 

[jrichker]

Did you put a fresh coat of thermo grease on the back of the TFI when you installed it?

 

[spyder2455]

the supplied grease was applied when I installed the module... I will get it tested as soon as possible. As I was brainstorming on the situation I realized that this problem started ever since my alternator caught fire and the fusible link that leads to the starter solenoid melted. I replaced the link and rewired the alternator using 6 guage wire and I'm wondering if its possible that the fusible link i replaced it with might be too short. I figure if this heats up it can prevent proper voltage from reaching my computer and ultimately stalling the car. Any thoughts on this?

 

[jrichker]

the supplied grease was applied when I installed the module... I will get it tested as soon as possible. As I was brainstorming on the situation I realized that this problem started ever since my alternator caught fire and the fusible link that leads to the starter solenoid melted. I replaced the link and rewired the alternator using 6 guage wire and I'm wondering if its possible that the fusible link i replaced it with might be too short. I figure if this heats up it can prevent proper voltage from reaching my computer and ultimately stalling the car. Any thoughts on this?

I don't think it would make any difference, but a voltage check with a good DVM would tell immediately.

 

[spyder2455]

TFI tested ok after three tests(to heat up). I looked into a fuel pressure guage but they want 50 bucks for one so I figured I might as well buy one I can put on there permenately. Even though I have a new pump, bad fuel pressure is the only thing left I can think of.

 

[kr mstg]

Do you have a ignition system?? I had a MSD that was going bad and after i would drive it a while and slow down it would die. It took anywhere from 10- 20 tries to get it start up again. Needless to say i took it off and wired it up st8t. I never had the problem again.

 

[Mike97gt]

keep in mind it could also be a connector somewhere that is causing this or a relay overheating.

 

[spyder2455]

I do not have an aftermarket ignition... and I agree that it might be something electrical due to the effects of heat on old connections/relays. On thursday I plan on installing a stage 1 cam, and along with it I am going to get an adjustable regulator a fuel pressure guage. When I pull it apart I'll be able to check all my connections thouroughly and maybe I will run across something.