

Remanufactured fuel injection pump, cross-ref 3976438. Bench-tested before shipment.
Quote within 24 hours. Send a photo of your nameplate and we will confirm the exact match.
3976438 is supplied as a remanufactured replacement fuel injection pump. Cross-reference numbers: 3976438. Application recorded for this part: Fits Cummins — 6CT. Every injection event depends on this pump producing pressure at exactly the right moment. Because it also carries its own lubrication, poor supply pressure and fuel dilution do disproportionate damage — which is why the supply side should always be checked alongside the pump itself. Expect extended cranking especially when hot, hesitant throttle response, smoke that persists rather than clears, timing that drifts or will not hold, and in some cases fuel in the sump or a pump body running unusually hot. Eliminate the cheap causes first: filter condition, lift pump output, suction-side air leaks, fuel quality. Only then have delivery quantity and timing tested before committing to a replacement unit. Fitment notes: this unit must be timed to the engine, not simply bolted on. Never force the shaft to align — turn the engine over to meet it. Prime the system before cranking, fit a new drive seal where specified, and verify supply pressure from the lift pump before start-up. Running a dry pump, even briefly, causes damage that no warranty will cover. What we do differently: every core is stripped to components, inspected against wear limits and measured before anything is reused. Worn parts are replaced, not cleaned and refitted. After reassembly the unit is bench-tested — delivery, return flow, opening pressure and leakage — and only units inside specification are dispatched. We can send the test sheet for your order before it leaves. Every remanufactured unit carries a 12-month warranty.
| Part number | 3976438 |
| Condition | Remanufactured (not a genuine OEM new part) |
| Application | Fits Cummins — 6CT |
| Process | Disassembled, cleaned, measured, wear parts replaced, machined to specification |
| Bench test | Delivery, return flow, opening pressure and leakage recorded before dispatch |
| Warranty | 12 months |
Three very different things are sold under similar descriptions. Here is what separates them, and what to ask before you buy.
Read the guide →The pump sets pressure, quantity and timing. Here is how wear shows up, and the checks that separate pump faults from supply faults.
Read the guide →Water, dirt and misfuelling damage common rail components differently. What to check, and why cleaning the system matters as much as replacing parts.
Read the guide →