Passenger side cylinders not firing?

[jlansaw]

I have a friend that has a 2001 F450 7.3. He claims the cylinders on the passenger side aren't firing. The truck will start fine and run but seconds after the engine is running the passenger side cylinders drop. He says there is fuel, power and oil pressure. He has replaced sensors, wiring harnesses, and I'm not sure what all but he still can't find the cause.

I'm not a 7.3 mechanic but I am curious about what is causing this. Anyone have any ideas?

[jc82chevyman]

need a little more info does he have oil pressure to the heads whats the condition of the IDM it sounds like a connector is coming loose some where if it starts

[jlansaw]

Sorry but what's the IDM?

[m-chan68]

Originally Posted by jlansaw

Sorry but what's the IDM?

Injector Driver Module

[jlansaw]

I'll check it out tommorow and post again tommorow night...........

[Bad Night]

A friends truck was doing that . Check the wiring harness where it come across the driver side valve cover (look for rubbed raw spot) if okay there follow it down to where it is close to the shock mount , again look for rubbed raw spot . His truck had a rubbed through wire there . It was shutting down one bank of the IDM .

[jlansaw]

Originally Posted by jc82chevyman

need a little more info does he have oil pressure to the heads whats the condition of the IDM it sounds like a connector is coming loose some where if it starts

OK, supposedly oil pressure at idle on firing side is 750 psi, dead side is 1500psi. IDM has been changed, still does the same thing. Wiring harness has also been changed.........

[jc82chevyman]

okay that is odd how are you measuring the oil pressure difference between the heads

[Gascan]

I have heard of a bad injector causing the IDM to send a message to the PCM, reporting a short. Then the PCM will then tell the IDM to stop firing a whole bank. This makes sense in this scenerio, because it runs fine for a couple moments. You can test the resistance in the injectors on that bank. You need to measure between the signal pin and the common return pin on the valve cover harness. It should read ~2.9 ohms.

[jc82chevyman]

yes please try that Im very curios to know for sure what is causing this problem