HELP - Strange IDM Problem
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HELP - Strange IDM Problem
Let me start from the beginning. 3 weeks ago, my truck was only running on the passenger side cylinders. So I replaced all the wiring harnesses on the drivers side, plus one glow plug pin that was burnt. It ran fine for about 50 miles, then it started doing the same thing, it would shut down the drivers side cylinders intermittenly until eventually, it was running on the passanger side cylinders all the time. So I changed the IDM. The strange thing about it, the old and new IDM will only work when it is not grounded to the fender. If I dont mount it, it runs fine. And if I mount the IDM to the fender, it shuts down the drivers side cylinders. I understand that there has to be a short somewhere, but has anyone witness this problem before? Any suggestions?
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Originally Posted by fordf350crazy
Let me start from the beginning. 3 weeks ago, my truck was only running on the passenger side cylinders. So I replaced all the wiring harnesses on the drivers side, plus one glow plug pin that was burnt. It ran fine for about 50 miles, then it started doing the same thing, it would shut down the drivers side cylinders intermittenly until eventually, it was running on the passanger side cylinders all the time. So I changed the IDM. The strange thing about it, the old and new IDM will only work when it is not grounded to the fender. If I dont mount it, it runs fine. And if I mount the IDM to the fender, it shuts down the drivers side cylinders. I understand that there has to be a short somewhere, but has anyone witness this problem before? Any suggestions?
I think you've got a broken wire somewhere in the insulation, or a bad connector on a wire. So that when you bolt the IDM down.....it separates, and it makes contact if it's left in a natural state. Start the engine and move the loose IDM around some......if I'm right.....it should start cutting out. Hope this helps.
Mountain Pass
Joined: Feb 2002
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From: Northern IN
Ohm each of the pins on the drivers side valve cover connectors to ground to check them for correct values. On the 95 there are two connectors, each with 5 pins. Pins 1 & 5 are for the glow plugs, and should have from 2-5 ohms resistance to ground. Pins 2, 3 and 4 should not have any resistance to ground (infinity), and if they do you still have a wiring problem somewhere.
I don't recall exactly, but I think pins 2-3 and 3-4 should be about 25 ohms to each other. Pins 2 & 4 are each for an injector, and pin 3 is the ground reference for these two injectors. This means that if any of these 3 pins is grounded somewhere, you will get a very similar reading from all three of these pins to ground.
If this checks out ok, you probably have a problem somewhere in the external wiring harness between the engine and IDM. Good luck.
I don't recall exactly, but I think pins 2-3 and 3-4 should be about 25 ohms to each other. Pins 2 & 4 are each for an injector, and pin 3 is the ground reference for these two injectors. This means that if any of these 3 pins is grounded somewhere, you will get a very similar reading from all three of these pins to ground.
If this checks out ok, you probably have a problem somewhere in the external wiring harness between the engine and IDM. Good luck.
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Thanks MDB. I will try this process of elimination.
I wish that the shop had done this before buying a new IDM. Now I am stuck with a brand new $850 IDM. Anyone interested in buying this at a discount?
I wish that the shop had done this before buying a new IDM. Now I am stuck with a brand new $850 IDM. Anyone interested in buying this at a discount?
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