Truck stalled, wouldn't restart, then started fine hours later

[PlayingWithTBI]

Can a faulty ignitiion control module allow the truck to run sometimes, and not run sometimes (like when the engine gets fully warm)?

Yepper

 

[stutaeng]

My brother asked me if I could help him change the fuel pump on his C1500 because it wouldn't start. He pulled it to my house because he didn't have air tools. When we took off the bed I checked for 12V and I could hear the pump run with engine key on.

I then checked for spark and he didn't have any. I want to say he also didn't have injector spraying...i can't recall. After a few other basic diagnosing I found online I was down to pick up coil or distributor (I'm not familiar with TBIs, as I've never owned any.)

He got a new distributor from the local parts store, dropped it in and it fired up. I think he had to buy a timing light to set timing, but truck I think is running fine.

I don't know if this part would cause intermittent problems like you describe.

 

[Schurkey]

Can a faulty ignitiion control module allow the truck to run sometimes, and not run sometimes (like when the engine gets fully warm)?

Yes.

Or do they usually just die and the truck won't start ever again?

That's a possibility. They can fail intermittently, or permanently.

Don't rule out a failed ignition coil, or a failed pickup coil. Symptoms are similar. In fact, the most-common cause of a failed ignition module is that it was murdered by a failed ignition coil.

 

[PlayingWithTBI]

I then checked for spark and he didn't have any. I want to say he also didn't have injector spraying...i can't recall. After a few other basic diagnosing I found online I was down to pick up coil or distributor (I'm not familiar with TBIs, as I've never owned any.)

Yes, the ICM is involved in both spark and injectors' firing. When the ECM sees DRPs (Distributor Reference Pulses) it fires the injectors. The ICM converts the sine wave signal from the pickup coil to digital signal and fires the ignition coil. So, when it fails, it can lose one or both functions.

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[ShannonTxBurb]

I was on the highway at about 80 MPH and my engine just quit. It wouldn't start again. I noticed no oil pressure when cranking so added oil. (Yep, only an idiot lets the oil get that low.) After I got oil in and started seeing pressure when it cranked, it still wouldn't start. I pulled the air cleaner cover and the injectors are not firing, or they aren't getting gas.

We got froze in so I haven't looked at the fuel pump relay or fuze yet. I'm wondering if the oil pressure switch going off sets something in the ECM that needs to be cleared. Anyone know?

94 Burb, 5,7 TBI 2WD

 

[letitsnow]

I was on the highway at about 80 MPH and my engine just quit. It wouldn't start again. I noticed no oil pressure when cranking so added oil. (Yep, only an idiot lets the oil get that low.) After I got oil in and started seeing pressure when it cranked, it still wouldn't start. I pulled the air cleaner cover and the injectors are not firing, or they aren't getting gas.

We got froze in so I haven't looked at the fuel pump relay or fuze yet. I'm wondering if the oil pressure switch going off sets something in the ECM that needs to be cleared. Anyone know?

94 Burb, 5,7 TBI 2WD

Can you hear the fuel pump run when you turn the key on?

 

[Schurkey]

I was on the highway at about 80 MPH and my engine just quit. It wouldn't start again. I noticed no oil pressure when cranking so added oil. (Yep, only an idiot lets the oil get that low.)

Seems that the fuel pump relay system has failed. You're running the fuel pump from the oil pressure switch. No oil pressure = no fuel, engine dies.

In this case, perhaps a good thing.

After I got oil in and started seeing pressure when it cranked, it still wouldn't start. I pulled the air cleaner cover and the injectors are not firing, or they aren't getting gas.

Test fuel pressure.

I'm wondering if the oil pressure switch going off sets something in the ECM that needs to be cleared.

Nope.

 

[Supercharged111]

I'd try the free thing first: idle it until it dies again then put the original coil back in. If the coil was swapped just because, then it's likely you traded a good OEM coil for a garbage Chinese coil.

 

[ShannonTxBurb]

I'd try the free thing first: idle it until it dies again then put the original coil back in. If the coil was swapped just because, then it's likely you traded a good OEM coil for a garbage Chinese coil.

Wrong thread?

 

[Supercharged111]

Wrong thread?

How?