Bad IPR or HPOP

gnxtc2 · May 18, 2017

Or something else.

2002 truck 7.3 with 280k

Helping a friend diagnosis a no start condition. The motor ran then all of a sudden it just shut down. Before I got involved, a friend suggested the HPOP was no good so they replaced it. Well....it looks like a used HPOP along with the IPR was installed. I was able to see that the HPOP gasket was new and the RTV for HPOP gear was fresh. They were just throwing parts on. After the HPOP swap, still had the same issue.

They shot it with ether. Truck started then died. Probably running on the ether.

So, I get involved and this it what I found:
- Hook a scanner no codes and only making 220 HPO.
- Engine LPO is 60 psi at the filter.
- HPOP reservoir is full
- ICP sensor is full of oil.
- Oil level is good
- Check all fuses...all good
- I isolated both heads and hook up a manual gauge. I was barely getting any readings.
- I deadhead the HPOP and I get nothing.
- Didn't confirm if the HPOP gear bolt was tight.

Now, I can't confirm if they re-used the IPR valve from the original HPOP. I'm trying to get the HPOP that was on the truck to confirm if the IPR was swapped.

I want to replace the ICP sensor. Hung up on whether to just replace the IPR.

If I apply 12v direct to IPR, the valve should close and HPO should max out.

Any other things to check?

Billy T.
gnxtc2@aol.com

79jasper · May 18, 2017

Definitely check the hpop drive gear bolt.

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dsberman94 · May 18, 2017

I'd check the bolt as well. A lot of guys won't get that tight enough if they're the type to just throw parts at it.

PSD POWER007 · May 19, 2017

Last time I had the issue, I pulled the VC's first to make sure the injector orings wasn't puking oil. All appeared good, so I ordered a new IPR from dieselorings.com I think it was. Came with the solenoid too. Slapped it in and it fired right up. Yours has to be the pump, gear, or IPR based on the info you've given. Check the ipr plug too. The isolator comes out over time and the wires arc on each other.

gnxtc2 · May 19, 2017

I gonna apply 12v to the IPR and see if it builds pressure.

Billy T.
gnxtc2@aol.com

doubledoor · May 19, 2017

Dead head the pump and full field the ipr and see what you get.

gnxtc2 · May 29, 2017

Applied 12v to the IPR valve and deadheaded the pump.....no pressure. HPOP reservior was full.

Billy T.
gnxtc2@aol.com

79jasper · May 29, 2017

Check the bolt yet?

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gnxtc2 · May 29, 2017

Not yet, that's next. Started to rain.

Billy T.
gnxtc2@aol.com

gnxtc2 · May 31, 2017

79jasper said:
Check the bolt yet?

Yep, it's tight.

Removed the IPR and set it on the bench. I hooked a jumper pack to the coil and there was no spark. The coil and/or the IPR didn't do anything.

Anyone know what the resistance is suppose to be on the coil?

Billy T.
gnxtc2@aol.com

79jasper · Jun 3, 2017

I can't remember the value exactly.
Something like 10-14 ohm.

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gnxtc2 · Jun 16, 2017

Installed new IPR. With the HPOP dead headed, HPO shot right up to 4K. :jammin:

Put everything back together and it started right up.

Gotta love it when people just start throwing parts and the same issue(s) are still there. Someone replaced the HPOP with a used one and re-used the IPR off the HPOP they took off. The coil on the first IPR was bad.

Billy T.
gnxtc2@aol.com