I have an '86 IROC with a 350 and TPI that was rebuilt less than 1000 miles ago. The cat, plug wires, plugs, distributor, coil, ignition module, injectors, EGR valve, EGR solenoid, EGR temperature sensor, intake air temperature sensor, TPS, IAC, MAF, ECM, fuel pump relay, MAF relays and just about anything else I could think of were replaced at the same time. Sometimes when it's hot, it cranks, but won't start. A spark tester indicates it has spark and a fuel pressure gauge reads 44 psi., so it has fuel. I did put a noid light on a couple of the injectors and it flashed, but only dimly. I also noticed that when the accelerator pedal was depressed, it didn’t flash at all. Shouldn't the noid light flash brightly and all the time? Anyone have any ideas?

 

sounds like heat soak to me. My car has a simmilar problem- along with everyother sb chevy i owend. Usualy its that the starter and the 'noid get to hot. Wrap them up with a heat sheild, and see how that treats you.

 

Pedal Depressed makes the engine depressed. Seriously, when it is depressed all the way, it is a clear flood mode thing. Max air in, no fuel to dry out the cylinders

 

How is the cranking? Is it weak or strong

 

It cranks very strongly and for a long time without slowing down so I don’t think it has anything to do with the starter. Thanks for the info about the clear flood mode. It explains why the noid light went out when the accelerator was depressed. I checked the injector signal with the noid light when the car was cold and the light flashed very brightly, so it means when the car is hot, and the noid light flashed dimly, the signal to the injectors is too weak to fire them. Is there anything between the injectors and the ECM or does the ECM fire them directly?

 

Could the battery be too drained after cranking that it cannot power other stuff properly too?

 

I had a hard starting problem with my 86 IROC when it was warm and I would also smell gas after I turned the car off. After I replaced my injectors the two problems disappeared.
Dan

 

Injector resistance will go up with heat....when the car is running the fuel passing through keeps the injectors cool but when you shut her down the heat will really settle in. I'd say the injectors are just too tired to fire when they're good and hot. Age does that.

 

I replaced the injectors with Accel 26# when the new engine was installed.

 

Try a set of Ford Racing ones. I can't say for sure but people have mentioned that they had problems with the Accel ones. What is the resistance of each injector when it is hot vs cold?