I need some help guys. I am new to the world of fuel injection. I bought an 89 Camaro Iroc Z with the 5.7L TPI motor. The car is all stock. I love these cars but i just don't know that much about them. When i bought the car it ran fine. a couple of days later after buying the car, I started having issues. The car starts right up when the motor is cold. It idles fine and does not stall. The problem is: after the motor is warmed up, if i shut the car off and then try to restart the car, it will not start. The motor cranks, it just doesn't start. Now if i pull the air cleaner assembly off and spray starting fluid in the throttle body it will start right up. So to me it wouldn't be an ignition problem but i am unsure because i really don't know much about fuel injection. I have always owned carbed cars. Hopefully someone can give some ideas on what this could be.

thanks,
Mike

 

It sounds like it is running the F/P off of the oil pressure switch because the relay is bad.
Get someone to stand behind the car while you turn the key on and listen for the pump to run for 1.5 seconds at key on. (key needs to be off for at least 2 minutes first)
If the relay goes bad, it uses the oil pressure switch as a backup.
When the oil heats up there might not be enough oil pressure to turn on the switch during cranking, but after the engine starts there will be.
That's probably the reason the car was up for sale; nobody could figure this out.

 

Sounds like the fuel-pump relay isn't priming the pump. When warm, the oil is thin and takes longer to build pressure when cranking.

 

My exact problem dude. i've been told its the fuel pump going bad. then i was told maybe its a leaky injector causing a flood, sorta like a carb would do? Taking it to a shop soon to get a final answer!! You should do the same, its definitely the fuel system. Let me know man. GOOD LUCK
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Okay gentleman.... sounds logical,,, but how do we FIX IT NOW!!
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Hmmm.... sounds like that may be it guys. so how do we FIX IT!!!

 

thanks for you help guys but i have another question. I will check out the fuel pump relay but which one is it? I looked in the engine bay and i see a couple of different ones. One is near the battery and then there are two on the firewall on the driver's side. Is it one of those or is it somewhere else? thanks a million.

Mike

 

They change up the mounting of the relays on different year models.
Here's a pic of the 3 relays on the firewall of my '88.
The F/P relay is the "rectangular" one. The other two are "oval" shaped.

 

Do this test first. If the pump runs at key-on, it's not the relay.