Saturday, March 24, 2012

DT 466 Diesel Engine Fuel Pressure Test

DT 466 Diesel Engine DT/DTI/DTA (C Engine) Fuel Pressure Test with a Robert Bosch 'MW' and 'A' Fuel  Injection Pump.

The primary reason for checking fuel pressure is a performance complaint which could be caused by low fuel pressure or restricted flow. This simple test will help determine firstly if the filters are plugged or if there isn't enough flow to the injection pump.

The fuel pressure test on a DT 466 Diesel Engine with the Robert Bosch injection Pump is a straight forward procedure that requires a fuel pressure guage that reads up to 160 psi connected to the vent plug located on top of the secondary fuel filter housing. 

DT 466 Diesel Engine Fuel Pressure Testing Procedure

The fuel pressure has to be a minimum of 20 psi at engine high idle (no load). High idle is full throttle (linkage contacting high idle stop), transmission  in neutral.

If the pressure is low... replace the fuel filters. Retest fuel pressure and if the readings have not improved the next step is checking the 'transfer pump inlet restriction' (coming up in my next post).

The DT 466 is a mechanical injected fuel system and as you can see troubleshooting is pretty straight forward. No laptops required :)

The first reaction to low power complaints is to replace the fuel filters and most of the time that will be the cure. It's also interesting to see how much of a difference the filters make before replacement. 
The next post will be all about testing the DT466 for 'transfer pump inlet restriction'

Comments Welcome!


Volkswagen Servicing Coventry said...

The life of a diesel engine is generally about twice as long as that of a petrol engine due to the increased strength of parts used. Diesel fuel has better lubrication properties than petrol as well.

Anonymous said...

I dont know if my last comment went through.I would like to know if a leak in the enjector pump would cause a diesel engine from starting. The engine will turn over.Its on a LB75 New Holland backhoe. p.s my Email is