I'm frying IDM modules and need help. I've fried 5 while trying to figure it out. Ohm testing hasn't shown any issues. Alternator tested ok, many inspections have left me scratching my head. What an i missing? Anybody else have this issue before?
IDM issues
- Thread starter NMartin
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PTSUPERD
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Hey man. Welcome to the site. What is year and rundown on your truck?
My truck is a 1997 2wd F350 7.3. E fuel, Baby Swamp injectors, cx racing intercooler, 6637 filter, hydra chip with custom tunes, hx cross over line, 4" exhaust, rebuilt turbo with 360° bearing and 7 fun billet wheel, heat wrapped up pipes and down pipe, IssPro gauges.....I know these things may not make a bit of difference but I wanted you to know everything. I blew a cooler boot just before the turbo with high boost a day or so before this started, if that can affect anything. First idm was the original one but had the 140v mod when it quit completely. Borrowed a friends idm and it fired right up. Got a 100v replacement and it fried immediately. Borrowed a 100v from a friend and it ran fine for 2 weeks. Bought a 100v & 140v so I could give his back and fried both immediately but it will run on them, just not firing on injectors 2 & 4. Note I've checked the alternator which is fine, installed a new Dorman uvch under the drivers side, tested all ohm resistance at the idm plug and they all read 2.8 ohms which is within tolerance, I believe. I'm now taking all ground wires loose and reinstalling them before I check ohms again.I'm at a loss, and scared to install another idm. Used the good borrowed one one last time for a buzz test, which showed the injector solenoids to be good, and started up the truck for a possible contribution test and I think I fried it too. It will again run but only in 6 injectors. I need help guys, badly.
79jasper
Active member
Probably the Dorman uvch.
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lincolnlocker
Well-known member
he said its testing out within spec... for now...
what codes do you keep coming up with?
live life full throttle
lincolnlocker
Well-known member
to your knowledge? are you not scanning it with a good scanner?
live life full throttle
79jasper
Active member
I'm still going with the junk Dorman uvch.
I've heard some are wired wrong. Beings the two cylinders right next to each other aren't firing.......
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I've heard some are wired wrong. Beings the two cylinders right next to each other aren't firing.......
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Honeydew_OBS
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Did you put a new pigtail in when you put the dorman gasket on?
lincolnlocker
Well-known member
Arisley
Moderator
I ohm checked the harness at the idm plug with everything hooked up, except the idm. I am getting 2.8 ohms at each connection with open lines on the grounds. When I put the Dorman in last winter, I did replace a plug on the under hood harness but it is on cylinders 6 and 8.
old man dave
New member
The UVCH pair of injectors would be 2&4, so that would seem to be a bad UVCH harness. The usual bad IDM failure would be one whole bank at a time, not 2&4.
Try a Ford UVCH harness this time, Dormans are known to have a wiring error in them. Also check the engine harness to valve cover to UVCH connections for burnt pins/broken wiring on the 2&4 wiring string.
Try a Ford UVCH harness this time, Dormans are known to have a wiring error in them. Also check the engine harness to valve cover to UVCH connections for burnt pins/broken wiring on the 2&4 wiring string.
David N
Active member
My brother's truck kept frying IDM's a few months ago. Somehow the harness checked within specs but when he would crank the motor, the UVCH would have a short in it. Im guessing maybe the vibration of the motor was doing it? Have you pulled the valve covers yet? Once we removed the valve covers we could smell a burnt solenoid and then we found the harness with burn marks.
UPDATE:
I installed a new Motorcraft uvch, new old engine loom from a running part out and had the injectors sent back to Swamps for warranty inspection. I added a new ground from the ground block at the starter to the frame and cleaned all ground contacts under the hood. So far, it is back up and running with no issues. I know I threw a lot at it at once and don't have a definitive answer as to what the problem was, but I feel confident it was in the uvch and/or engine harness.
Thank you guys for all of your help with this!
I installed a new Motorcraft uvch, new old engine loom from a running part out and had the injectors sent back to Swamps for warranty inspection. I added a new ground from the ground block at the starter to the frame and cleaned all ground contacts under the hood. So far, it is back up and running with no issues. I know I threw a lot at it at once and don't have a definitive answer as to what the problem was, but I feel confident it was in the uvch and/or engine harness.
Thank you guys for all of your help with this!
