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Discussion Starter · #1 ·
Back in May I needed to get my 96 inspected for re licensing. On the way to the inspection shop, about 5 miles away, I noticed it fish biting a couple of times. Didn't think too much of it as it had been sitting all winter. With more use, the fish biting got progressively worse until the truck wouldn't run at all. I knew the lift pump was working and I had plenty of fuel. First step was to put the scanner on it. I don't remember the codes but there were 2 that had to do with the injection pump. The following is an approximate list of the steps I took in trying to figure out what was wrong. Nothing made any difference until the last step.
1. Switched to known working PMD.
2. Switched to new PMD.
3. Switched to new PMD extension harness
4. Removed the noise reducer filter thingy.
4a. Unplugged optical sensor.
5. Went through the Accurate Diesel checklist to determine if it was something in the wiring.
6. Called Fred at Badger Diesel and ordered a new IP.
7. Fast forward 2 months and my IP came.
8. Installed new pump, no change.
9. Went through all the same diagnostics as I did on old IP.
10. Called Fred a Badger Diesel and he said it had to be something in the wiring because he knew the IP was good. He suggested that I take a pick and tighten up and clean all the electrical connections going to the pump.
11. Tightened and cleaned all connections.
12. Out of desperation I went to the parts truck and pulled the 2 wiring harnesses that run from the firewall to the IP.
13. Installed the "new" wiring harnesses.
14. Truck started right up.
15. Ordered the new wiring harnesses.

These wires have been laying in oil and being subjected to engine heat for 25+ years. Even though it passed all the tests, in the end, it wasn't the pump. In the future I will never replace the IP before I try a different harness and the IP wiring will be routed above the intake manifold for easy access.

Ronald Reagan fan
5,303 Posts
Yes the harnesses take a beating for sure.Especially when placed under the intake manifold.I bought a couple new harnesses from glagulator that allowed me to route the wiring on top of the intake manifold which allows it to escape the heat trapped in the V of the engine.
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