But it didn't.
CK5
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Really need some ideas on this ! Random dying issue
- Thread starter Chevk587
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- dying no injector tbi
Boo. That sucks
Nope it didn’t but now I have a spare lol , distributor if that’s not it loose wire somewhere .
wasted wages
1 ton status
Do the TBI distributors still have vacuum advance on them ?
Under load ( like going uphill, pulling on to the trailer ) the vacuum advance may be pulling in and moving the plate with the module and that's when the break in the wire shows up...
just a thought....
Under load ( like going uphill, pulling on to the trailer ) the vacuum advance may be pulling in and moving the plate with the module and that's when the break in the wire shows up...
just a thought....
It does sitting at idle while we were on the phone. Then fires up and idles for 45 minutes.
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What potential failure in the GM TBI system would cause no signal to both the fuel pump and injector?
He jumped the fuel pump and the injector still wouldn’t fire during this condition. I don’t know much about these GM TBI systems but this finding should narrow it down.
He jumped the fuel pump and the injector still wouldn’t fire during this condition. I don’t know much about these GM TBI systems but this finding should narrow it down.
I told him I now think it is the new, crappy aftermarket ICM. Needs to find an AC Delco version. Everything else has been bypassed and/or checked.
I have a new distributor I’m just gonna throw it in and see how it goes I’ll keep you posted appreciate the help .
No reference signal from the distributor. If the injectors dont pulse when cranking, the ECM isnt seeing the distributor turning, so wont fire them. That's the module most likely.
The oil pressure switch only turns the pump on or off, and is redundant under all circumstances with the relay. Both the relay and the switch are working to keep the rig running. If the relay fails, the switch will turn the pump on when oil pressure reaches ~4psi (extended cranking time). If the switch fails, you won't know until the relay does too. Obviously not the issue here though. If the rig wont run with one or the other unplugged, the other one is bad.
Same thing I told him, here's the kicker. When he unplugged the connector from the switch, it kept running. Would restart if it was disconnected. So I go out to the Jimmy while on the phone with him. Fire it up and unplug the switch wire. Kept running. The Jimmy is bone stock. Stock harness and everything. Restarted without it plugged in.
Or if the switch is working properly, you can unplug the relay while it's running and it will continue to run.
There is no warning that the switch has failed unfortunately, you could drive for ten years without knowing it was dead, until the relay dies. So many ways to force the pump to run though, it's not that big a deal if that does happen.
I guess the switch is a good thing for the person that never goes under the hood, but about worthless for those who do.
There is no warning that the switch has failed unfortunately, you could drive for ten years without knowing it was dead, until the relay dies. So many ways to force the pump to run though, it's not that big a deal if that does happen.
I guess the switch is a good thing for the person that never goes under the hood, but about worthless for those who do.
But doesn't a low oil pressure safety switch shut the truck off if there is low oil pressure. Like if you unplug the wires. The ECM should read that as an open switch and shut the engine down. Does not do that. But if he jumpers those 2 wires for the switch, the fuel pump runs all the time. Even key off.
It's not a safety switch. It solely exists in case the relay fails. It is wired in parallel with the relay...both have battery 12v going to them, oil pressure closes the switch and/or the ECM commands the relay to send power to the pump. Either will work independent of the other, and working properly, both are providing 12v to the pump when the vehicle is running.
You can jumper either the switch or relay connector terminals and force the pump to run regardless of ignition switch position.
You can jumper either the switch or relay connector terminals and force the pump to run regardless of ignition switch position.
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I new about jumping the relay. Never heard of the oil pressure switch feeding directly to the pump also.
Good info thanks
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Module is worth a shot and if not it never hurts to have a spare.
Ok changed the distributor no luck still died . So In changing it and messing with my ignition it seemed to have some issues changing it next .
Well I’m stumped it’s gotta be a wire somewhere ! Broken or something I’m not sure . Super frustrating.
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Start with wires that are exposed to the most heat or movement, I redid my wiring for my fuel pump the other day and re-routed some wires that come up the back on the engine to the plugs mounted on the firewall. There is at least one in line fuse. I was thinking if I have a problem I will start looking in this area first. Just throwing darts. Intermittent problems suck.
Yes they do
