HPO issue

Derek@Vision Diesel · Jun 11, 2011

What causes the ICP to jump to a default of 2400-2500 after about 20 seconds of cranking?
Truck wont fire, it will sit at 20-40psi for about the first 15 seconds you crank then randomly it jumps to 2400-2500. If the IPR is sticking it will automatically freak out and default itself?

Tom S · Jun 11, 2011

I think the magic default number is 2465 from memory that the computer suddenly uses. You will have to do some diagnostics to see where the oil is being bleed off at.

Derek@Vision Diesel · Jun 11, 2011

Tom S said:
I think the magic default number is 2465 from memory that the computer suddenly uses. You will have to do some diagnostics to see where the oil is being bleed off at.

Yeah i will have to. Doesnt it seem like a sticking IPR though!? Definitely could be air in the system also, but id think after having it started 3 or 4 times and driven a couple miles it would start easier than 2 rounds of 20 seconds

Tom S · Jun 11, 2011

I have no personal experience with a sticking IPR but I could see that being a possible cause of your issue. Do you have a spare to toss in there?

Derek@Vision Diesel · Jun 11, 2011

Tom S said:
I have no personal experience with a sticking IPR but I could see that being a possible cause of your issue. Do you have a spare to toss in there?

I do have one, but its loaned out to a buddy. I am trying to get it back as we speak to try that out. I dont see any other possibility unless a injector oring is SOO far gone that its just free flowing past

Derek@Vision Diesel · Jun 11, 2011

Anyone else?

Blowby · Jun 12, 2011

Check to see if you have oil in the res, if not how many miles on the LPOP? What is the LPOP pressure?
If you have oil in the res, check the pressure in the rails.
If you have pressure in all above look at the ICP sensor.
If no pressure:
Look at the oil, drain a little in a clean container and look for flakes of anything that could cause the IPR to stick.
If oil looks clean replace IPR.
HPOP could have failed.

Derek@Vision Diesel · Jun 12, 2011

Not sure on the mileage of the LPOP, i used one off another block i had. Could that be causing these issues?
Remember the truck only has 10 or so miles on it.

I got it to fire up yesterday after a hard crank or two, drove it all around with no chip and its definitely running better. Got it up to temperature and did a couple hard runs. But its still starting hard!
The rails and the HPOP res are full

Blowby · Jun 12, 2011

Strokeorcroak said:
Not sure on the mileage of the LPOP, i used one off another block i had. Could that be causing these issues?
Remember the truck only has 10 or so miles on it.

I got it to fire up yesterday after a hard crank or two, drove it all around with no chip and its definitely running better. Got it up to temperature and did a couple hard runs. But its still starting hard!
The rails and the HPOP res are full

You still have air in the system. You need to drive it and the starting should correct it's self.

Derek@Vision Diesel · Jun 12, 2011

Blowby said:
You still have air in the system. You need to drive it and the starting should correct it's self.

You probably are right! I just was worried a little because doing injector swaps and that sort of thing always make it a little hard to start but its nothing like this. Ive never had a 7.3 be this hard to start

SkySki Jason · Jun 13, 2011

I lost 3gals of engine oil when the exhaust wheel decided to exit the turbo a few weeks ago - and after I got it all back together I was stressing out for much of the 800mi back home because ICP was low and IPR duty cycle was over 60%....

It gradually returned to normal and I just laughed at myself for studying all the damn gauges so hard (not quite Joe 'yet', but 4 on a-pillar plus ScanGauge II). Nothing like having a problem so far from home to get ya to pay attention!! I was surprised how long it took to get back to normal, even towing at +20k GCVW driving hard.

Derek@Vision Diesel · Jun 13, 2011

SkySki Jason said:
I lost 3gals of engine oil when the exhaust wheel decided to exit the turbo a few weeks ago - and after I got it all back together I was stressing out for much of the 800mi back home because ICP was low and IPR duty cycle was over 60%....

It gradually returned to normal and I just laughed at myself for studying all the damn gauges so hard (not quite Joe 'yet', but 4 on a-pillar plus ScanGauge II). Nothing like having a problem so far from home to get ya to pay attention!! I was surprised how long it took to get back to normal, even towing at +20k GCVW driving hard.

Yeah its quite possible i need to just drive it! I worry about things probably too soon