Alright here's an update guys, swapped a known good PCM out of my buddies 97' 7.3 and got crank to come up using his PCM so I know my PCM needs to be rebuilt. I didn't have the good scanner when I did the swap so I couldn't read ICP Pressure or IPR %. Only tach. That being said knowing I had the tach issue fixed I still couldn't get the truck to fire with his good PCM. Truck still isn't filling the High Pressure Oil rails. It pressureizes the rails a little bit because I cranked the motor for about a minute then unscrewed one of those fittings on top of the rails (because it still wasn't trying to start or puffing any smoke) to see if it was filling the rail with oil but the rail was bone dry. It did hiss when I took out the plug however so it was pressureized with air. I didn't check the voltages on the IRP with his good PCM in there but I did with my bad one and got 11-13v on the one wire and 0 v on the other. At this point I'm going to guess and say my IPR is stuck shut/not working? I say this because I pulled the one High Pressure Oil line off the HPOP and only a drop of oil came out so the HPOP isn't even pumping oil to the lines on the actual pump. I'd like to think it's because the IPR isn't allowing the oil to the lines because it's stuck shut or broken and stuck shut. What do you guys think now knowing all this?

I sent the PCM out to get rebuilt and will expect that back in a few weeks, also waiting on the IDM to return because they sent me one with a fault. So yeah I'm thinking/hoping it's the IPR at this point but what do you guys think?

 

Don't even sweat it until you get the new pcm. If it ran fine with your friends pcm, it's likely the ipr not receiving signal.

 

The IPR could be stuck open

 

82F2urd It didn't run at all with my buddies PCM. It got a tach signal with his PCM but still wasn't filling the high pressure oil rails. I couldn't read the ICP/IPR data as I did not have my fancy scanner when I swapped the PCM. I only had my buddies tuner which only read tach. The oil rail pressurizes with air as I can hear it "hiss" when I crack the fitting on the rail off just no oi in the raill. Bone Dry. It IS getting oil in the reservoir about half an inch from the top and the HPOP gear is 100% torqued down to spec so the oil is there and the HPOP is spinning with the motor but it's pumping zero even into the lines feeding the rails.

Lead Head would a stuck open IPR cause no oil at all to get to the lines feeding the oil rails?

 

A stuck open IPR will bypass all of the HPOP oil as far as I know.

 

First question would be are you building base oil pressure? Your oil pressure gauge is showing pressure correct? If you aren't building base pressure, the high pressure is not fed. Also skimming through I saw you say you were cranking for a minute or two at a time, you shouldn't do that. Crank for 10-15 seconds and wait 30 and repeat.

EDIT:
If you are getting base oil pressure and you are 100% sure it is a high pressure oil problem it is either an HP pump, HP oil system leak or your IPR valve.
You can try removing the IPR and capping off the port for it with a pipe fitting. Unplug the UVC harnesses so the truck will not start and crank it over. If the ICP is above 500 at this point you need and new IPR.

 

I am building base pressure because the reservoir drains if it sits for a few weeks with out cranking and fills right back up in like 15 seconds after the first crank after sitting for that long a time. That being said the gauge on the dash does move a bit, not to a normal operating position but it moves a bit.

I do crank about 10-15 seconds with rest time in between, i meant by the minute or two was that was about how long total I'd be cranking the motor over in those 10-15 second periods.

What harness is the UVC? I'll have to take the IRP out and get a fitting and bring the good scanner home to test the ICP with the IPR out. Thanks for the input by the way!

 

My mistake, I breezed through and thought you'd said it ran. It sounds like it's time to take the ipr out and check it.

 

Normally the oil pressure gauge will show full normal pressure when cranking. The UVC harness is the valve cover gasket (under valve cover harness) along with the injector harness.

 

Ok guys so I sent my PCM out to get refurbished after swapping the known good PCM in and getting crank numbers from the known good PCM. Well they called me and said they can't find anything wrong with mine and that there's nothing they can do for me. So I'm getting my old PCM shipped back to me with nothing fixed on it. Are PCM's relatively interchangeable or no? Cause we have two different PCM's listed on one of the parts warehouse websites at the shop with lists of model numbers that will work with each PCM but the model number of my PCM isn't on either list. Are PCM's relatively interchangeable or do I need one with my exact model number?

 

As long as it's from the same year and type (manual or auto) it should be fine.

 

ipr sensor is what was wrong with my 7.3 when i got it. try it

 

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