Hpdi fuel rail capacity

[Holy Smoke]

Trouble shooting my HPDI and I have a question , I have it narrowed down the canister filter or the high pressure pump. I can run for a minute or so before dropping rpms. ( vst holds 50 psi and hp pressure drops as the rpms drop)

Any guesses as which it is ? The canister filter or hp pump.

Motors turn 5700 rpm's and the port drops rpms after a minute or so

How long will the motor run at full rpms on the just the fuel in the rails or how long with it run the the fuel rails and some of the canister filter

Nevermind it's a stupid question

[rodbolt17]

couple of seconds ,maybe.
the HP pump draws NO fuel.
it only pressurizes what the VST feeds it.
if the VST holds 50 PSI yet the HP pressure drops its either the medium pressure filter or the pump.

[boscoe99]

Maybe the filters within the HP pump itself.

Here is a link to a procedure that explains how to replace them. I would certainly start there. After first replacing the medium pressure filter if it is not known to be in good condition.

3.3L hpdi secret filters removal

[Holy Smoke]

That is my plan I will be replacing the medium pressure filter tomorrow and hopefully I do not have to dig into the hp pump quite yet.

[Holy Smoke]

medium pressure filter replaced....running perfect

[boscoe99]

Thanks for the feed back. Glad you found and solved your problem.