Cold, fires right up, let run for 5 minutes, shut off, try to start, cranks over like 10 times then fires up, let run for a little bit more, shut off, try to start, just cranks and no start.

5.7L TPI

Just replaced the ignition coil and rotor and ignition module in attempt to fix this, didn't work


So what could the problem be?? I pressed on the fuel pressure valve thing and it sprayed fuel out so i guess it has fuel pressure.


All tips/help is greatly appreciated!

 

Just went out to start it after it sitting for roughly 15-20 minutes, tryed starting, fired up, let run for like 20 seconds, shut it off, then it wont start again.. wtf!

 

It's a sensor, somewhere. I'm not knowledgeable enough of what they all do to say which, but getting a new o2 sensor first isn't a bad start.

I hear a lot of things rely on that o2 sensor.

 

Thanks for the reply Horizon, ill look into that.

Any other ideas anyone ?

 

A bad oxy sensor isn't going to keep an engine from starting, as it reads the exhaust gases after the engine is running (and warmed up). Have you checked for spark when it goes no start? Sounds like something may be overheating, either ignition, or the fuel pump, or the pressure regulator. Checking for pressure at the fuel rail the way you did doesn't tell you if you have enough pressure to spray the injectors. You need to check it with a gauge.

 

Well I just checked the for spark with a screw driver, has spark, and checked the fuel rail pressure with a fuel pressure gauge, has fuel pressure(45psi).

So the injectors must be not firing right? I'll get a noid light from school on monday and test out the injectors..

Since the injectors aren't firing, then the PCM must be fubar'd right?

What about VATS.... the car has vats.. and the resistor pellet in the key is MISSING! but it shouldn't start at all without that resistor??





thoughts?!

 

I'm glad I said that, now, because I didn't know it reads after being warmed up. I should have known that.

 

have you tried flucuating the gas pedal while cranking to see if that has any affect? it could be that the ecm isnt seeing operating temp and is still injecting the fuel to start a cold engine and might be flooding it out. i think 89 was the first year without a cold start injector. i know my car has 3 temp sensors. one for cold start, one for ecm/fan, one for gauge. yours should have at least two. the ecm on may be bad

 

I hope its the ECM and not security related.. Im gunna test with a noid light when i get home and ill post what i find out.

ECM is only like 100 bucks on summit right?

 

The car ran before with the pellet missing from the key, correct??