P-PUMP CUMMINS SHUTOFF SOLENOID SWAP

HELP! MY TRUCK WON’T START!

- JASON SANDS

So there we were, hundreds of miles from home, pulling a trailer, with a truck that wouldn’t start. Geez...aren’t 12-valves supposed to be reliable!? As it turns out, it was no big deal, but a nonstarting truck can definitely give you that sinking feeling. We’ll explain.

One of the more common problems on virtually all ‘94-’98 Dodges, as well as some generators and tractors, revolves around the P7100 injection pump. While the pumps themselves are extremely reliable and hardly ever fail, the shutoff solenoid that is mounted to the pump fails often. Our ‘95 project truck dubbed the Green Monster already had its solenoid replaced somewhere down the line, but it still failed yet again (probably because it was a Chinese-made knockoff verson). The shutoff solenoid activates a governor lever that allows fuel to flow into the pump, which allows the engine to start, but also to stop, because cutting off the fuel is how virtually all diesels are stopped from running.

So our solenoid was bad, but fortunately, we weren’t dead in the water. Thankfully, even if your solenoid is weak, you can still almost always start the truck by turning the key on, walking around underneath the hood, and then manually moving the governor lever back towards the firewall of the truck. It’s a pain (and something that would be horrible in traffic) but at least that will get your truck going down the road again.

We could tell by the blue wiring cover that our factory shutoff solenoid had already been replaced at some point. Still, it was hit-and-miss on working, so it needed replaced.