How long does the truck take to crank when hot? Should be longer than cold, but really no more than 5-10 seconds. Mine take 2-3 seconds hot. If you've got a good hot start I would probably lean away from a HP oil leak. Your ICP & IPR look good for hot idle.

Sounds like the IPR is either getting stuck (faulty IPR) or there is something stuck in it. I would pull the IPR and inspect it before going any deeper into the motor.


1600psi ICP is cruising down a flat highway unloaded at 75mph. Climbing hills at WOT I've seen just over 4000psi.

 

Cold starts in the 2-3 second range... good.
Hot starts in 2-3 second range .... good.
NO ICP oil in connector .... good.
No hunting ICP.... good.

HPOP seal, park nose down and see. If quick start after sitting all night, could be the seal... no change, move to something else.
Long cold start, could be injector or dummy plugs. Oil in the hole after pulling ICP when cold, left bank is good. Pull the plug in the right valve cover, oil there is indicator your standpipe and dummy plugs are good.

That leaves HPOP seal and IPR and of course injector o-rings and nipple cups.... an air test will show those if leaking.

My move would be IPR and for my truck (same issues), it will be what I look at next.

 

Are you running a tune when you get those numbers?

I run SRL+ in my truck and get about 1600-1800psi on WOT with 85IPR. This is because the HPO system is working a lot harder to make more power. If i put the stock tune back on the truck, it runs 3800-4000psi and 60IPR at WOT.

 

There is a PID to test this if you have access to Autoenginuity or IDS:
ICP_DES or ICP desired

Comparing desired to actual is a great way to check for HPO leaks.

If someone has a Scangauge/Torque formula for ICP Desired PID please share it.

 

I'll try the stock tune... I'm running SLR Extreme and Atlas 40 on the FICM. Now that you mentioned that, probably my issue.

Hopefully the OP is in the same boat?

 

I am running the extreme street tune from innovative i believe its been a while since i got my tunes but yes i was going to tune to stock and check it

 

I'm almost certain that's why you are seeing low ICP numbers. Same goes for watson. It scared me a little at first too when i checked ICP with my SCT X4 and saw how low it was with the IPR maxed. A quick flash back to stock assured me nothing was wrong. I actually got the idea from the 7.3L section, because that engine does the same thing, only even more pronounced. It's simply that the HPOP can't quite keep up with the high demand that is put on it with hot tuning. It won't hurt anything though, except hold the performance back a bit. If we were to run higher volume HPOPs and fuel pumps, we'd likely see less ICP drop and have more power, without changing tunes.

 

Brandonrr I want to say thanks for the idea to switch back to stock and check my ICP as you stated when I changed back the ICP was great showing 3900+. It also fixed an issue that I was fighting with my fan kicking on at 199-200*. So now I think ill be looking for a new Tune I can handle the ICP pressure drop but the fan change is something that really annoys me to death as i have a Mishimoto 200* t-stat.

Thanks for all the help from everyone on this thread.

 

Actually, I don't think the tune makes changes that causes the HPO system pressure to drop or sag. I think the tune causes the PCM to "See" the lower number (it lies to the PCM) and increase the IPR duty cycle, causing the injectors to see higher oil pressure sooner.

 

I can deal with the changes on the HPO system as far as "Seeing" lower ICP its the fan duty cycle change that is wrote into the tune that is making me think about getting a new tune. I hate hearing the fan running all the time because the truck is running 200* ect which is where I want it to be.

 

While i agree with you, there is also a bit more to the whole equation. These trucks use HPO to pressurize the fuel. When you add more fuel with hot tuning, you need more oil volume on the injector side to do it. While the 6.0 (especially 05-07) has a stronger HPOP than any year of the 7.3, it still has its limits. Part of the hot tuning "fools" the computer into delivering more oil to the injectors. It's hard to tell how hard the HPOP is actually working (or struggling) in this case.

My point in the earlier post i made was to return to stock if you want to compare with the "normal" values when diagnosing potential problems.

My boost also never shows more than 28psi with SRL+, simply because the tune "fools" the boost reading to avoid setting a CEL. Its supposed to hit 30+psi, but without a plumbed in guage, i honestly don't know the real peak boost numbers. Tunes have their diagnostic downsides for sure. I always recommend going back to stock for any engine or tranny related diagnostics.

 

Excellent advice!