5.7L TPI '90 Iroc, fresh rebuild (3000miles), new fuel pump, & filter. On occation, after running great and getting warmed completely, when you shut it off and re-start the car, it acts as if it's not getting fuel. Fuel pressure is confirmed at 43lbs at the fuel rail, good spark via plug wire #1-header. What gives? It will idle sometimes and just die, or if you touch the gas at all, it acts like it's starving for fuel and dies. Am at a loss and almost wits end with it.

 

 

Water temp sensor and oil pressure sending unit replaced already. Ohm'd injectors and checked TPS voltage through it's travel. 47lbs of fuel pressure that doesn't drop off quickly with key off.
I am beginning to think the ECM is toast....Thoughts?

 

Tried a new ECM tonight to no avail. I also tried to pull codes and all I'm getting is the normal "12" code repeatedly. Am rapidly running out of ideas on what to do.

 

CTS that sends engine temp to computer is seperate sensor to those two for the gauges .Is located at front of intake under TB

Have you pulled a spark plug to see whether they are wet or dry ?
Does pressure hold with key off?

Did you check injector resistance when hot as in when problem occurs?

 

https://www.thirdgen.org/forums/post...381-post6.html

https://www.thirdgen.org/forums/post...996-post2.html

https://www.thirdgen.org/forums/tech...-when-hot.html

 

I removed plug#1 and it did have slight carbon buildup, but not excessive. It did smell of gas, but wasn't wet. Then I took my coolant temp sensor off and it OHM'd 0.0. I heated it with a lighter to see if the resistance changed. It did not. OK, I went to the the parts store and it read much differently than a new one, so I installed a new one. No difference. Still looking for the culprit/problem.

 

Removed ignition module, cleaned, and regreased. The car will start and run fairly smooth as long as I squirt a bit of gas into the air intake ports..... I am sure I still have a fuel injection issue. Have a code 42 now after re-installing and starting. Ignition module?

 

If the ignition module were bad, I think it would not run or would be idle much rougher when it's running off of the added gasoline. Maybe the code set when I unplugged it?

 

To answer earlier question...The fuel pressure does hold with the key off. It takes quite a bit to see any drop at all.
I can get it to start, but I can't get the car to run long enough now to heat anything at all......but the headers. Ouch.

 

Got it running with a squirt of fuel into the intakes ports. It ran for about 10 minutes at a weak idle and shut off. If I touch the throttle, it dies. I diconnected the batt and the code is cleared.
Am now at a loss again. It runs entirely TOO smooth to be injectors or a spark issue. FP is still 47lbs with key on and holds there. SOMETHING is not telling the injectors to fuel enough DAMMIT.

 

Now a code 44 after it idled, somewhat weakly, for 10-15 minutes. Oxygen sensor SHOULD read lean if it barely has enough fuel to run at all.

 

Disconnected battery today and put a new ignition control module in it today. Still same results. Cranks and dies immediatly. It will run if I continue to squirt gas slowly into the plenum. Am now at a loss. Don't really know where to go from here now.

 

IF I had am injector shorted out or fried, and it was pulling too hard on the ECM if I disconnect 1 injector at a time, would it try to run or throw a code?

 

Have not gotten alot of response here. Thought I'd post what I found anyway. It may help others.
Today I pulled injector wires 1 at a time and tried to start. 1, 3, 5, 7 first, then 2, 4, 6, 8. When I got to #8, the car started normally. While idleing, I plugged it back in and the car died immediatly. Go figure. 1 shorted injector killing the whole friggin car. Time to replace then with the Ford 19lb injectors I guess.
Thanks to those who posted to help.

 

I did mention above to check injector resistance.
A grounded injector will cause the ECM to shut down the whole injector bank to protect itself

Contact FIC for cheap injectors
http://fuelinjectorconnection.com/shop/

 

Cool. Once again, Thank you for the help.