Join Date: Dec 2008
Location: Tyler, TX
Thanked 407 Times in 347 Posts
What he said ^^^^!
Also, the HPOP is the pump that supplies the power to inject fuel into the cylinders. The pressure of the oil leaving HPOP is controlled by the PCM via the IPR valve (Injection Pressure Regulator). MOST cases of low ICP (HPOP oil pressure) are a result of a wiring problem to the IPR valve, wearing out of the IPR valve, or loss of oil volume (ran engine out of oil, bad engine oil pump or oil pressure regulator). With really high miles and long oil drain intervals, the HPOP can wear out, but they DO NOT cause a "No Start/Hard Start" condition unless it is HOT. For cold starting problems, the HPOP is about the LAST component to suspect, but it is often one of the first replaced (in error).
'93 F-250 HD, 7.3L IDI, 5spd - FARM TRUCK
I Support: Trailer brakes an every axle over the towing vehicle's GVW; CDLs for RVers; Safety inspections for ALL vehicles and 6 axle trucks (97K GVW proposal).
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote - Benjamin Franklin
I vote for LIBERTY!