92 chevy lumina euro has spark no injector pulse

[jdtm84]

Was called today to look at a car that wont start its a 92 chevy lumina euro with the 3.1 v6 automatic 4 door. The car has a new crank sensor recently installed ran well for a while and now has no injector pulse. Checked for spark its good. sprayed starting fluid in the intake and it fired for a second acted like it wanted to run and then died. Checked for fuel at schrader valve it has fuel there I dont have a fuel pressure gauge but it sprayed pretty good. I'm not real good with electrical but thought maybe the ICM under the coil packs could be bad I have one off a running engine on my shelf but wanted to see what other people had to say first. Any suggestions?

[jdtm84]

So I did some more work on this car today and found one wire had been burned and taped up I checked in my book and found that the ICM has nothing to do with the fuel injectors at least from what I can tell from the wiring diagram. I'm getting +12 volts from both the pink and black wire witch is normal and also from the green and blue wires witch is suppose to be the ground pulse. I don't know what would cause this but I'm thinking it may be a bad PCM at this point. anyone ever had this issue and how did you fix it?

[Tech II]

If the ICM is not sending a reference signal to the PCM, you will not get injector pulse....

[Schurkey]

'92 is batch-fire...right? The 3.4 is batch-fire through '93, but went sequential in '94.

One dead injector can cause two more to not fire. Two dead injectors kill the whole engine.

[Tech II]

Shurkey is correct, also.....if the engine is Multiport, one shorted injector will take out 3 injectors....what you can do is check injector resistance......1-3-5 are in one parallel circuit, 2-4-6 are in the other circuit.....

Each injector is 12 ohms......but when 3 resistors are in parallel, they equal 4 ohms......You can take your readings at the injector harness connector by the alternator....If one is open, it reads 6 ohms....if two are open, it reads 12 ohms.....if it reads zero, there is a shorted injector or harness(a short will cause too much current flow and the computer quad driver will shut down the injector circuit)...mice are known for making a nest under the upper plenum, and eating the insulation off of the injector harness....or an injector could be shorted internally....