Well its been 7 months now since my PSD been laid up ....... and 7 months of work and no luck ........ It all started when I changed my ICP valve a while back ..... the engine was smoking badly and running poorly and I changed the valve to improve oil circulation ......... the truck refused to start since then and so far i have gone through the process of elimination to find the problem... wich included changing the ICP back to original one, Changing the HPOP, The LPOP, the ICM, all of the injectors, The IDM, the CPS, The Main Computer module, Under Valve cover wire harneses, wire harness connectors, fuel pump, Under fuel bowl wire harness, Had main engine wire harness checked, Fuel filter changed, Ive overfilled oil crankcase and raised back of truck to test for cracked oil pickup tube, Read all fault codes and nothing of any significance....
Ive gotten the truck to start a few times since changing the HPOP but it wont run for long and it takes quite a bit of cranking to get started .... I think ive narrowed the problem to poor oil pressure ... I have installed on the cylinder head oil plug a pressure guage and when cranking it barely goes up high enough to activate injectors firing... then when it finally starts the pressure reads about 900 psi and at higher RPM's it never gets over 1200 psi .... eventually it falls back so low that the engine quits ....... Remember now this is with a new HPOP a new LPOP New Injectors ...and I checked and rechecked for injector o ring problems and poorly seated injectors ..... Ive checked for fuel pressure and that is fine ........ Is it time for an overhaul or should i just sell it as junk....... I hate to just give away my baby and after spending so much money I prefer to just get it running again ...... What do you guys say???

 

I think a compression test would be needed before you scrap it.
Those HPOP readings are too low IMO. There are 2 HPOP styles, are you sure you installed the correct one?
What is the LPOP oil pressure while cranking?
If the de-aeration valve in the front engine cover is loose the HPOP may or may not stay full. Once it falls out it won't run at all. Not common, but it has happened.
Does the HPOP stay full?

 

Did you check the o-rings on the IPR or change out the IPR? I did not see any mention of any work on the IPR. If your engine serial number is 201680 or lower (last six digits) you need a HPOP with the anit-drain back valve built in and a IPR with "Edge Filtering".

 

WOW!!!!!!!!!!
I thought my 3 month no start was bad but you got it even worse than me.
Im thinking about getting rid of mine , its a 02.

 

So what do your pressure gauge say for the HPOP and Low pressure oil when cranking? Any smoke out the tail pipe? fuel pressure? Do you have any way to read codes or PCM data? Any scanner to run a buzz test?

Where are you located?

 

Guys I really appreciate the responses .......... The IPR was replaced also..... The oil pressure guage on the dash board usually takes a while of cranking before it reads oil pressure.... after a bit of cranking the guage would jump from zero to center of guage .... this happened before I changed LPOP and still after it was replaced.... Also I dont have any problem with the HPOP resovoir maintaining oil, it has always been full whenever i checked it.
I had a buzz test done and all injectors firing.... also fault codes show no problems...... HPOP reading while cranking is about 500psi.
Plowhand I will check out your info .... maybe you have something there.