Diesel Injection Pump Timing & Calibration
The Difference
Is Microseconds.
Diesel power depends on injecting fuel at the exact moment of compression. If your timing is off by a fraction of a degree, you lose power and generate smoke.
Dial Indicator Method
For Bosch and Zexel pumps, we use precision dial indicators to measure plunger lift, setting the static timing to within 0.01mm of factory specs.
Spill Timing
For many Yanmar and Perkins engines, we use the "spill timing" method—watching the exact moment fuel flow cuts off to determine the injection start point relative to flywheel degrees.
Diagnosing Smoke
White smoke at idle usually means timing is retarded (late injection). Black smoke or loud "knocking" means timing is advanced (early). We adjust to clear the air.
Calibration Protocol.
A meticulous process for mechanical perfection.
TDC Finding
We locate Top Dead Center (TDC) on the compression stroke using flywheel markings or piston stops to establish a baseline.
Measure
Using a dial gauge or spill pipe, we rotate the engine to see exactly when injection currently occurs compared to spec.
Adjust
We loosen the injection pump mounts or adjust shims to rotate the pump body, advancing or retarding the timing.
Lock & Test
Once perfect, we torque the pump down and run the engine to verify smooth idle, easy starting, and clean exhaust.
Smoother Running.
Eliminate the shake and the smoke.
Supported Systems.
Expertise in mechanical injection systems.
Common Questions
Does timing change on its own?
Yes. Gear wear, timing belt stretch (on some models), and pump internal wear can cause timing to drift "late" (retarded) over thousands of hours.
Can't you just listen to it?
"Ear tuning" is a guess. We use factory-specified tools to set timing to the specific degree. Guessing risks melted pistons or cracked heads.