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Discussion Starter · #1 ·
Hello all,
My f250 has a rough idle, misfire situation.
I turn the truck on and immediately it misfires, shakes, and sputters. Brought it to my diesel tech at ford, he replaced the IDM twice (installed a new one still had the same issue, idm was replaced again because codes were all leading to the idm)
both injector harnesses (harnesses were reading 0 ohms to 800ohms when stressed) I got my truck back ran fine for 2 days, no codes injectors ran perfect no misfire/sputtering only thing i noticed was the turbo wasn't as "whistley" as it was before this mess started. By the third day started sputtering a bit and by the time I drove 5 minutes to the shop it was full blown back to misfire and shaking like when I first brought the truck in. Codes ran to all injectors, the injector harnesses, the pcm and the idm.
Has anyone had anything like this happen before?
 

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What codes?
Post them and we can give you pointers on where to look. The service manual has specific pinpoint tests based on the codes. If you don't follow them, you're just throwing money at the parts you're swapping.
 

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Discussion Starter · #3 ·
Hello all,
My f250 has a rough idle, misfire situation.
I turn the truck on and immediately it misfires, shakes, and sputters. Brought it to my diesel tech at ford, he replaced the IDM twice (installed a new one still had the same issue, idm was replaced again because codes were all leading to the idm)
both injector harnesses (harnesses were reading 0 ohms to 800ohms when stressed) I got my truck back ran fine for 2 days, no codes injectors ran perfect no misfire/sputtering only thing i noticed was the turbo wasn't as "whistley" as it was before this mess started. By the third day started sputtering a bit and by the time I drove 5 minutes to the shop it was full blown back to misfire and shaking like when I first brought the truck in. Codes ran to all injectors, the injector harnesses, the pcm and the idm.
Has anyone had anything like this happen before?
What codes?
Post them and we can give you pointers on where to look. The service manual has specific pinpoint tests based on the codes. If you don't follow them, you're just throwing money at the parts you're swapping.
I dont have all of them but i can try to contact my dealer to get them, the only ones I have on hand are
P1293
P1294 (high side idle bank)
P1298 (idm)
The pin point tests were all done As far as I know for each code. Each injector keeps reading a high side idle bank
I can see if I cant get a full list of codes when he runs them.
 

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If you've replaced the IDM (twice - which pretty much proves it wasn't the problem), and the injector harnesses, about the only thing left is the valve cover gaskets and possibly the wiring harness outside the valve covers. It sounds to me like you have some burnt pins that sort of "healed" by removing and replacing the connectors, but still weren't 100%. I would check the outside injector connectors, the wiring to them, and the VC gasket pins. Replace what doesn't look absolutely clean. Also check that the connectors latch on to the VC gasket securely. Sometimes the pinpoint tests don't pinpoint everything. You have to use your eyes to be sure things make good connections.
Another tip: If you use a bunch of dielectric grease on the pins, it can actually cause problems. (Don't ask how I know that.) Don't goop it on the pins. Just the seal on the connectors.
 
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