Diesel Injector & Injection Pump Repair in Jerome, ID

Last fall, a potato hauler called us from the Walmart parking lot here in Jerome. His 6.7 Cummins had gone soft on power, was knocking at idle, and blowing white smoke on a cold start — and now there was diesel showing up in the engine oil. It barely got him into town. Two injectors had failed. We tested the set, pulled the bad ones, and had him back on the road before harvest got busy. That is how we do diesel injector repair in Jerome — test first, fix what is actually broken, and give it to you straight.

Injectors and the injection pump are the heart of how a diesel runs. When they start to go, the truck tells on itself: rough idle, hard starts, a drop in power, worse fuel mileage, and smoke that was not there before. Catch it early and the bill stays smaller. Wait too long and a failing pump can push metal through the whole fuel system.

Signs your diesel injectors are going out

Most folks come in describing the same handful of problems. Any of these is worth a look:

• Hard to start, or a long crank before it fires
• Rough idle, or a knock that sounds like a hammer tap
• White or black smoke, mostly on startup
• Loss of power on hills or under a load
• Fuel mileage falling off for no clear reason
• A diesel smell in the oil, or the oil level creeping up

Diesel Injector Repair

We start with a test, not a guess. We check each injector for how it sprays, how much it leaks back, and how it holds pressure. That tells us which ones are bad and which are still fine. Then we pull the bad injectors, clean up the bores, set new or rebuilt injectors with fresh seals and hardware, and reset the fuel trims so the new parts read right. A single injector can be a same-day job. A full set on a stubborn engine runs a day or two.

Injection Pump Repair (CP3 / CP4)

The high-pressure pump feeds every injector. A lot of trucks run a CP3, which is a tough pump that takes a beating and keeps going. Newer Power Stroke and Duramax trucks run a CP4, and that one can come apart and push metal shavings through the whole fuel system. If a CP4 lets go, the job gets bigger — pump, injectors, lines, rail, and a full flush — because any grit left behind kills the new parts. We tell you up front whether you are looking at a simple pump swap or a full fuel system job, and why.

Cummins, Power Stroke & Duramax Injector Repair

We see all three in the bay every week — 5.9 and 6.7 Cummins, 6.0 / 6.4 / 6.7 Power Stroke, and LB7 through L5P Duramax. Each one fails its own way. LB7 Duramax injectors weep, the 6.0 Power Stroke has its own injector quirks, and a tired Cummins lift pump starves the CP3 until it gives up. We keep the right test gear and the common parts on the shelf, so your truck is not sitting for a week waiting on a box.

Why diesel injectors fail faster around here

Magic Valley diesels work for a living, and that shows up in the fuel system. Farm and dairy trucks pull in dust and the odd tank of dirty fuel, and grit is hard on injector tips. Long idle hours on cold mornings wash the cylinders and wear parts early. Winter brings water in the fuel and gelling on the coldest days, which is rough on pumps and injectors both. Highway haulers running the I-84 corridor at full weight just put more hours on everything. None of that is your fault — it is the work these trucks do.

What to expect: testing, time, and cost

Here is how a visit goes. We hook up the scan tool and run the fuel system tests. We call you with what we found and a written price before we order a single part. Most injector jobs land between a day and a couple of days. A CP4 failure with a full flush takes longer and costs more, and we walk you through why. If the truck still drives, we can often get you on the schedule fast. If it is down, ask about our mobile mechanic service — for many farms and job sites we can come to you.

Injector and pump work often ties into the rest of the diesel repair we do, from fuel system work to turbos and head studs. If we find something else once we are in there, you get a call first.