Hi all

I have not worked with a lot of TDI PD but I was asked to look at this one.

Hard starting after standing for a while, with extended cranking, once running there are no drivability faults reported.

No fault codes

Injector signal on cranking present

Initial primary fuel pressure ignition on 0.5 bars
Fuel flow of approximately 1.5 litre/min

Tandem pump pressure slow to build, at 1.7 bars engine starting to fire.
Engine starts to run at approximately 2 bars by this time cranking could be 30 seconds or more.

Primary pump pressure has now risen to 1 bar

At idle tandem pump pressure fluctuating at 4 bars + or – 0.25 bar

Tandem pump pressure at 1500 rpm 7.5 bar

On turning off engine tandem pump pressure drops rapidly to 1.5 bar and then slow to decrease further.

Primary pressure when engine turn off increases to 1.5 bars and holds

Would I be right in thinking this may be caused by injector seals leaking?

Many thanks
David