[mweiman]

I have a truck in that I was told died and would not restart. When it was dropped off I cranked on it a long time and once the oil pressure gauge came up it started. It takes a long time for icp to build when cranking but once it does it starts. It seems to have oil in the reservoir for the hpop. Took the oil pressure switch out and oil is down about 1/2 inch from the top after sitting overnight. Also took the check valve out and everything looks fine. Pulled the ipr to check it and ended up replacing it but no change. I cranked on a good running truck yesterday morning cold and the base oil pressure gauge took a long time to come up also. I originally thought I had an issue with base oil pressure but thinking that is not the issue. Am I checking correctly to verify the hpop reservoir is full? If it is full should it at least start and die regardless of base oil pressure?
Thanks for any input.

 

[NoRalPh]

Instead of removing the EOP sensor, take the little Allen plug out of the lid to measure the oil level (I'm not sure it's going to be any different, but I've never tried a measurement from that hole). 1 inch down is fine from there...

Keep in mind that the PCM will not trigger the IDM to start before ICP pressure crosses about 500psi. This is much more important that EOP, is that what you're seeing?

 

[Hydro]

Numbers for the ICP voltage would be good to know, but sounds like there is a leak in the high pressure system or bad pump. I would lean towards a bad pump, since it builds pressure when the base oil system gives it "a little push" on the pressure.

 

[mweiman]

That may make sense about the oil pump. Yes once ICP hits 500 or so it will fire up. We actually had the allen plug out also. Oil level seemed the same in both. I may pull the truck out and warm it up to see if it will restart hot. It does start a little better after it has been running.

 

[Hydro]

What is the ICP voltage and IPR % when it is starting and when running?

 

[mweiman]

key on icp voltage .2 engine running .9 to 1 volt
pressure idling 580-650 psi -It seems to jump around more than a normal one but may still have some air in it from changing the regulator..

 

[mweiman]

It does start right up after it has been running and is still at 50 psi(scan tool) after being shut off for a couple minutes. It does get the long crank back after 1/2 hour or so of shutdown.

 

[Hydro]

How long do you have to crank before the pressure gets above the 500 threshold?
Have you checked the little tin nut on the ICP to see if it is holding the coil in place?
I don't see the IPR% -- what is that reading?

@NoRalPh would it worthwhile todo an air test on this 7.3?

 

[mweiman]

10-15 seconds of cranking. Tin nut is tight, just replaced ipr. I probably shut it off 10 minutes ago. About 100 psi icp after shutdown. Still had 10 psi after 10 minutes.

 

[mweiman]

IPR % 15 at key on and about the same idling. It hit 36 cranking but it fired up since it has been running. Mid 30's if I revved it once running.

 

[NoRalPh]

I'm confused though....

All the talk about 100psi and then only 10psi after 10mins,,, this is ICP pressure? There's no residual pressure is there? I mean, you shut it off and the ICP drops to "0"! (it has to, the IPR can't ever shut off the bleed down completely).

But let's put that aside for a moment and review. You start it the morning while monitoring ICP & IPR values. You crank for 10-15 seconds before the ICP crosses the 500psi level and, all the time that the pressure is sub 500, the IPR doesn't rise above the mid 30's percentage? But it's all normal once you're warmed-up. Within 1/2hr it will build pressure quickly and start quickly.

NONE of that sounds right to me

 

[mweiman]

Yesterday more than once I had the truck running and shut it down then key back on engine off. ICP would be 100 psi or so and then slowly drop to 0 psi over a 10-15 minute time span. That was monitored with a scan tool but to me that means it doesn't have a major leak. I will recheck in the morning ICP % and pressure on a cold start. It had been running when we talked yesterday so I didn't have a chance to monitor a long crank time. I did get it out of the shop today and drive it. It does seem to restart fine hot.

 

[mweiman]

I started it this morning after being out overnight. It fired up a lot better but still maybe twice as long of crank time as normal would be. Ipr percent hit 50 before it fired. Icp pressure was like 1500 when it started and settled back to 600 or so. May still have some air in it from ipr replacement. I drove it about 7 miles yesterday.
I think the truck originally may have died because it was low on oil. It has a bad leak at the oil dipstick. It has started better since replacing ipr but not as good as it should. I may drive it some more to verify air is all out.