About this part
3931537 is supplied as a remanufactured replacement fuel injection pump. Cross-reference numbers: 3931537, 3931538, 3931599. Application recorded for this part: Fits Cummins — 5.9L.
This pump has two jobs that are easy to conflate: raising fuel to injection pressure, and metering the correct quantity at the correct moment. Wear affects both. The result is usually a combination of harder starting, drifting timing and visible smoke rather than one clean fault.
Typical indicators are progressively harder starting, particularly when hot, reduced power, smoke under load, erratic idle, and fuel dilution in the sump — the last one should always be investigated immediately.
Diagnose the supply side before blaming the pump. Restricted filters, a tired lift pump or air being drawn into the suction line will produce symptoms almost identical to internal pump wear, and are far cheaper to resolve.
Key points: align to the timing marks rather than forcing the drive, prime before cranking, renew seals, confirm adequate supply pressure from the lift pump, and bleed the system fully. Skipping any of these is where most comebacks originate.
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.
Specifications
| Part number | 3931537 |
| Condition | Remanufactured (not a genuine OEM new part) |
| Cross-reference | 3931537, 3931538, 3931599 |
| Application | Fits Cummins — 5.9L |
| 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 |
Fitment note. Several part numbers in this family look similar. Confirm the number on your
existing unit, the engine model and the machine or vehicle application before ordering. Send us a nameplate photo
and we will verify the match before dispatch.
All manufacturer names, symbols and part numbers are used for identification and cross-reference purposes only. We are not an authorised distributor and are not affiliated with the original equipment manufacturer. Products offered are remanufactured or new aftermarket replacement parts unless stated otherwise.
