I have a 1989 Iroc 305 TPI, with manual transmission. I have replaced the distributor (and the module), the ECM, Mass Air Flow, and the fuel filter. The injectors receive a steady and normal flow until the car is warmed up, then it stalls and shuts down. The fuel pressure is good and the voltage is good. Can anyone help me?

 

It sounds like you have replaced most of the components. It may now be time to start checking the wiring between them. Resistive connections usually increase in resistance with heating. That includes grounds.

You might also want to verify that the injectors have a 12VDC supply after the system heats up and you loose injetor firing. You'll need to check for both the 12V potential AND the voltage under load. You should be able to simulate load with a wirewound resistor or spare solenoid. If the supply voltage falls off with load, suspect the supply side of the circuit. If the 12V source remains constant under load, start looking at the ECM signals with an oscilloscope. Since you've replaced the ECM, it's not likely internal.

 

Thanks for your input. The mechanics that work on my car have been thinking thats what the problem is. Thanks!

 

Hey, sorry to jack this thread, but I have a 1991 TA 305 TPI, and it does the same thing, and I have changed damn near e v e r y t h i n g ! Still won't run after it warms up.

Vader, I don't quite understand what you mean about checking the 12VDC supply, and the voltage under load. Or more clearly, I dont understand how to check this stuff. Are you putting a meter on the injector leads? Sorry to be a pain, I'm new to this stuff, and am extreamly frustrated with my car right now. It has been not running for over a freakin' year now! (two summers shot to hell)

Thanks in advance for any advice, I appreciate any help I can get!

Chris.

 

Have you ohm'd out all the injectors? Since our cars are batch fire, one shorted injector can kill the whole system.

Just unplug the injector harness from each injector one at a time, and use an ohmmeter to verify them at 10-14ohms each.

 

Yep, thats also one of the things that I have changed. Three times to be exact, but hey, who's counting I am currently running Accel 19lb injectors. My car is all stock (except for a K&N filter) The ohms are 14.9 on every single one. Not one was off, even a tenth! My old stock ones were around 16.2
I swear if I had a match today . . . . . . .

 

Is there anyone else that may have some valuable input or explanation as to why this happens?

 

If you get this fixed, could you P L E A S E, P L E A S E, P L E A S E, tell us what the problem was? I am SOOOOoooo frustrated right now, and the mechanic that I go to worked on it for two days and told me to "get it outa' here" because he was spending way too much time on it and couldn't find anything.

Thanks for any help!

Chris.

 

when the mechanics figure it out and fix it, I'll let ya know

 

I told INSPECTOR 111 this in a private message, but it turns out that the 6th injector was bad in my car and was the main problem. But since I had that problem fixed, I had to replace my mass air flow sensor... the car ran great for about 2-3 weeks before I had to replace the MAF. i wonder how all this stuff messes up in the first place, lol. so, INSPECTOR 111, whats the latest on your car?