Hello,

92 Pontiac Firebird Formula 305

My car will not start at random times. If i let it sit over night and try to start it when i wake up, it starts fine and stays running. However, after i get to work and when i try to leave for lunch, the car will roll over but wont fire.

All fuses have been checked
Fuel Pump activates every time when i turn the key on.
Fuel filter already repalced
Battery Replaces
Security light is NOT on.
I can get it started with starting fluid and it will run til i turn it off and try to start it back up.

Any ideas on this?? This issue is driving me crazy. I dont want to get rid of the car, because when it does fire, it runs like a dream.


Please help!

 

Is it only hard to start when the engine is hot?

 

Also, you have the 305 tpi right?

 

It seems to be that way. Today it started right up after sitting for hours on end. I let it get warm....just below 220. turned it off, and it wouldnt fire when i tried to start it. I then replaced the ignition coil and it didnt make a difference....and yes 305 TPI.

 

Mine does the same thing. I would guess that your fuel injectors are leaking. If the injectors are leaking fuel into the cylinders its actually creating a flooded condition which is why its hard to start. However, if the engine sits for a while, like overnight, the fuel evaporates enough that the car will start easily. Next time you need to start the car with the engine warm try holding the throttle all the way open while your turning the key and release it immediately as soon as it fires. This will clear the fuel out of the chamber. If this works you can be pretty sure your injectors are leaking. You might want to check the resistance on your injectors but they may all give normal readings even if they leak. I've been driving my car like that for over a year and it doesn't seem to affect anything but hot starts.

 

After following this forum for the past year or two, i have come to notice something. Everytime there is a potential problem with fuel injectors everyone says to check ohm on each injector which is a fine recommendation, but just know that even if the readings are all within normal limits, that does not automatically rule out injector issues. They could be dirty, clogged, or leaking all of which will affect the performance of your engine.

 

Yes. Thought I made that clear.

 

I would have the ignition module tested - autozone can do it for free. I've seen them work when cold, but flake out when hot.

Edit: Nevermind, I just noticed that you said it will start with starting fluid, so it's not a spark issue. Could be leaky injectors, but it could also be fuel pump related. I would start by doing a leakdown test on the fuel rail. Put a fuel gauge on the rail, key on, key off, and see how long it holds pressure. If it leaks down pretty quickly, then there is a leak at the injectors or regulator.

 

i have the same problem. went thru and changed everything..... just did my fuel pump tonight and found the hose from the pump to the main fuel line had been ruptured. must've started as a small leak. by the way i have a 91 tbi. good luck

 

Try some seafoam

 

My car is having a similar problem I made another thread about it. So I just want to confirm this statement, if the car will start using starting fluid your sure I'm probly not dealing with a spark issue but instead a fuel issue?

 

Hello jmat2407!!

No matter how much starting fliud was added to the engine, if it had a spark issue it wouldn't fire, the starting fliud has to be "lit" by something, it doesn't create it's own spark!!