Rotary & distributor pump repair and calibration
We strip down, rebuild and calibrate Bosch VE/VP, Lucas/CAV DPA/DPS and Zexel rotary distributor pumps on dedicated test benches — restoring correct timing, metering and delivery for cars, pickups, light commercial and agricultural diesel engines.
One pumping element, shared across every cylinder
Unlike a common rail system, a rotary or distributor pump uses a single rotating plunger (or, on older DPA/DPS units, opposed plungers) to pressurise and route fuel to each injector in firing order. Timing, governing and metering all happen mechanically or electronically inside one compact housing, which is why wear in any one internal component — the cam plate, rotor, delivery valves or transfer pump — throws off fuelling to every cylinder at once.
These pumps are common on older and mid-generation diesel cars, pickups, vans and agricultural equipment across Qatar, and they respond well to a proper rebuild: most faults are wear-related rather than terminal, and a correctly calibrated pump can outlast a poorly matched replacement.
Typically Fitted To:
- Older diesel cars & pickups — pre-common-rail engines
- Light commercial vans — delivery & fleet vehicles
- Agricultural & farm equipment — tractors, pumps, generators
- Older marine auxiliary engines — gensets & pumps
Pump families we service:
Axial-piston distributor pumps common on cars, pickups and light commercial diesels. We rebuild the rotor, cam plate, governor and advance unit, then calibrate delivery and timing on the bench.
Opposed-plunger distributor pumps widely fitted to agricultural and older commercial diesels. We recondition the hydraulic head, delivery valves and governor to restore even cylinder-to-cylinder delivery.
Rotary distributor pumps used across Japanese and Asian-market diesel platforms. Full strip, wear inspection and re-calibration to factory delivery curves.
What a worn rotary pump feels like
Any of these on their own can point to the pump — together, they're a strong signal.
Hard or extended cranking
Worn delivery valves or a weak transfer pump reduce priming pressure, so the engine takes longer to catch, especially cold.
Rough idle or stalling
Uneven fuelling between cylinders from a worn rotor or cam plate shows up first as a lumpy idle, then occasional stalls.
Loss of power under load
Governor wear or internal leakage limits the fuel the pump can deliver at full throttle, flattening acceleration and hill performance.
Black or grey exhaust smoke
Advance mechanism or timing wear pushes injection timing off spec, producing incomplete combustion and visible smoke.
Fuel leaks or weeping seals
Shaft seals and O-rings harden with age; fuel staining around the pump housing usually means a reseal is overdue.
Erratic or surging RPM
A sticking governor linkage or worn flyweight assembly causes the idle or cruise speed to hunt up and down.
From fault-finding to a calibrated pump back on your engine
Every pump is bench-tested before and after rebuild, so the fix is verified, not assumed.
Diagnosis & bench test
The pump is mounted on the calibration bench and run to record delivery, timing and governing against factory spec, confirming exactly which internal components are out of tolerance.
Full strip-down & inspection
The rotor, cam plate, delivery valves, transfer pump, governor and advance mechanism are removed and inspected individually for wear, scoring and leakage.
Component replacement
Worn parts are replaced with OEM-standard components — seals, delivery valves, rotor assemblies or governor parts as needed — rather than a blanket unit swap.
Test bench calibration
The rebuilt pump is run back on the bench and adjusted until delivery quantity, timing advance and governing all sit within factory tolerance across the full speed range.
Refit & road verification
The pump is refitted, static timing is set on the engine, and the vehicle or equipment is run to confirm starting, idle and power delivery are back to normal.