I have verified that they have 12v and the injectors do click with a 9v battery. I've checked the resistance in the injectors, as well as the wires running to the injectors, and they are well within spec.
I have verified that they have 12v and the injectors do click with a 9v battery. I've checked the resistance in the injectors, as well as the wires running to the injectors, and they are well within spec.
Dumb question, but have you verified fuel is actually getting up to the injectors?
Don't force it, get a bigger hammer!
I have, and we've got fuel. I'm fairly certain that the computer is just not receiving SOMETHING that it needs in order to tell the injector circuit to ground.
Well, now I can't even get the software to connect to the computer. I'm taking tomorrow off, so I'm going to run over to the local junk yard and pick up another computer. I'm just convinced that I've somehow screwed this one up.
Picked up a new ECM and harness from said truck. EXACT SAME ISSUE!!! So, let me ask. Can a faulty oil pressure switch, or no oil pressure cause the injectors not to pulse?
when cranking, the oil pressure switch isn't used. I ran my truck for years without the oil pressure switch being connected. D14 and D16 from the ECM are what control the injectors A and B. Check for a crank signal on C9. that is what the ECM uses until the engine RPM's reach a running state. You may need an O scope.
Last edited by jim_in_dorris; 03-21-2017 at 07:56 AM.
Square body stepsides forever!!!
Thank you for your response! That is very helpful to know. One question about the crank signal. Where should the source be coming from? Is it different between a '91 and a '94? The only constant in all my tinkering has been the distributor, as an fyi. Maybe the issue is related to that (I have replaced the ignition module)
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