99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
2000 7.3 supr lost #8 inj. replaced had a fuel knock 1 cyl. pulled the g-plugs compression test 415-420 250K pulled inj bench tested 6 @75-85% 2 @70% now hard start hot easy cold
no codes and none in history good mileage 17-19 slight clatter at inital acc. not a knock. could this be related to the pressure relief valve orings at the high pressure pump bleeding off.
all orings were replaced and lubed. can the IPR bypass interally or leak down the static oil supply that is left behind after shut down making it necessary for the pump to fill the I system to achieve proper pressure for injector pattern
I think the IPR dumps back into either the HPOP reservoir or the oil pan, but not exactly sure right now. It is internal, though. What the IPR does is to block the relief port based on the signal it gets from the ICP sensor (via the PCM). If the o-rings are leaking, then the IPR won't be able to seal the relief port as it's asked to and the pressure won't build to the required 500 psi minimum.
If you have access to a scan tool that will monitor parameters, then set it up to monitor ICP, IPR duty cycle (how much it's closing) and crank the engine. IPR duty cycle should go to 14% immediately on key on, and the ICP should climb rapidly to 500 psi or more. If IPR duty cycle climbs real high, that would be a sign that there's a leak somewhere in the HP oil system.
If I pull the IPR and put an oring kit in it, which appears tobe basic, it could resolve the problem. visual inspection of the orings should reveal some condition good or bad.
If I pull the IPR and put an oring kit in it, which appears tobe basic, it could resolve the problem. visual inspection of the orings should reveal some condition good or bad.
If I were without a scan tool, that would be my first thing to try. Everything else is more work and $$.
I'm goin to scan it tomorrow and check the duty cycle. I use delvac 1 and have been for almost 100k. The 5w part bothers me in the summer so just in case the syn. oil doesnt hold up I use 1 gal of 15-50w to put me at peace. Thanks for your support I'll let you know how it turns out for the sake of the other PSD owners. jbow
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