Injector pump problems

A majority of difficult-to-diagnose problems with diesels are blamed on the injector pump. When pressed about what exactly is going wrong in the pump, very few mechanics or even injector pump service shops will be able to explain with is actually happening. The usual diagnosis is simply ‘bad fuel’ or ‘we don’t know’.

To appreciate the complexity of an older style injector pump watch this clip:

To appreciate the complexity of a modern, common pressure-rail injector pump watch this clip:

A few examples of injector pump problems we have encountered:

Problem: Vehicle has tapping sound, seems to be coming from the injector pump. The sound has become progressively worse over a 4-month period, with power starting to be affected.
Mechanic’s Diagnosis: Needs a reconditioned injector pump due to bad fuel.
Actual problem: Needs a reconditioned injector pump due to rust in the tank making it past the fuel filter and injector pump strainer; consequently the rust has gouged parts of the pump.
Solution: A reconditioned injector pump

Problem:Vehicle hardly running, blowing smoke and sounding very bad.
Mechanic’s Diagnosis:Needs a new injector pump.
Actual problem:Poorly made biodiesel had glycerine falling out, standard diesels do notrun on glycerine.
Solution:Drain the fuel from the tank and injector pump. Change the fuel filter and add fresh, properly made biodiesel and drive away.

Problem:Vehicle hardly running, blowing smoke and sounding very bad.
Mechanic’s Diagnosis:Needs a new injector pump.
Actual problem:Poorly made biodiesel had glycerine falling out, standard diesels do notrun on glycerine.
Solution:Drain the fuel from the tank and injector pump. Change the fuel filter and add fresh, properly made biodiesel and drive away.

Problem:Vehicle running with a lack of power, feels like the car is dragging an anchor.
Mechanic’s Diagnosis:Biodiesel is no good.
Actual problem:Clogged fuel filter.
Solution:Change the fuel filter.

Problem:Vehicle running rough with a lack of power.
Mechanic’s Diagnosis:Needs a new injector pump.
Actual problem:Clogged fuel filter due to splash, in tank blending of cold fossil diesel with hotbiodiesel.
Solution:Change the fuel filter once and have a spare in case it needs changing again.

Problem:Vehicle has lack of power, can not get over 2000 rpm.
Mechanic’s Diagnosis:Needs a new injector pump.
Actual problem:Clogged fuel strainer in the tank.
Solution:Use compressed air to blow down the fuel line into the tank.