Issue: my 1995 E350 7.3L seems to have an electrical shut off that happens most commonly when the temp starts to make its way towards WOT.
1st time: Happened at full wot after running for about 15 to 20 minutes. I was in a parkinglot idling when it shut down like a key-off. It started up again immediately 2 or 3 more times with about a minute of run time between each shut down. After #3, it was down for good for almost 2 hours. I replaced the IDM in the parking lot since I had a spare on hand. It ran amazing for about 2 or 3 minutes and then it randomly shut off again, no warning, no bogging down, no CEL. Got it pulled to my place after that and started my diagnoses. First I unplugged my ICP and let it run for about 5 minutes and it was fine, although the unplugged ICP did trigger my CEL to come on. I plugged it back in and ran it for about 20 minutes idling with no problem. I unplugged the ICP again and let it run for about another 30 minutes. I thought I may have resolved the issue, and tried driving it again. I got about a hundred feet and it shut off. It turned back on right after and I wasted no time parking it into a space and letting it be. Few days later I changed the CPS, and after a bit of idling, it shut off again. I work a lot so from this point forward there's 2 months of time in between this 1st circumstance and this post I'm writing today.

2nd time: about 3 weeks later I started it back up and moved it down a hundred feet into a different parking space that I usually park it in when I'm working on it. Well again, it went about 100 feet to that space and I was able to park it. I let it idle for a handful of minutes and it shut off as per usual. The temp was still cold.

From this point the next reasonable thing I wanted to check was the IPR. Well, being its a van, it was not easily accessible for me and I had to do quite a bit of pulling to get to it. I've had a fuel bowl leak for quite awhile and during the process of getting to the IPR I actually decided to gut the mechanical fuel system as a whole and convert to an E-fuel system from Marty's Diesel. I had the idea for awhile and this was an appropriate time to go ahead and fulfill that wish. Once everything was gutted, I went ahead and replaced my IPR, the IPR pigtail, and ICP (hadn't been replaced in over half a decade at least). I did find a concern in the IPR wiring; the 2 wires leading to the IPR seemed to actually be melted and had over an inch of bare wire exposed on each. I found that very concerning. I shortned the IPR harness and capped off the 3 wires that led to the fuel bowl. Anyways after everything was all said and done, the new fuel system install was successful and everything was put back together ready to roll.

3rd time: This is the day prior to this post. I got van running great after bleeding the fuel system of any air running the engine a few times. By the 3rd, maybe 4th time I ran it, it was running like the old beast usually did. I had it idling for about 7 minutes or so before I took it on a test run. I was running it around close by my apartment up and down a road for about 5 minutes and then bam it randomly shut off instantaneously as I was making a u-turn to go back up the road for a 3rd pass. Once I came to a stop I started it back up again and it started back up fine, and was good enough to get me back to my apartments, lil more than an eighth of a mile. From there I parked and let it idle for about another 6 minutes and then she cut out again.

Where should I go from here? Fuel is out of the question and its doing the same exact thing with the new IPR and ICP and spare CPS, so those are for the most part out of the question too.

 

Have to ask, were all the parts you replaced Motorcraft, or International/Navistar? It seems parts house parts do not play nice with these engines. Especially the CPS.

 

Pretty sure my CPS was Motorcraft, but the other 2 are cheap from ebay to see if it was going to yield different results. If the parts were subpar or faulty I would suspect the engine to run bad or not at all but I'm still dealing with the same issue prior to replacements.

 

Just a guess , You have a bad O ring somewhere in the HP Oil system If the IPR is new
.

 

your IPR wiring if shorted might have wrecked the wire else where in the harness


there are three relays that are the same under the hood fuse box

swap the PCM one and mark with tape or pen with a different one of the three
(contacts wear down from years of shaking)

Then check your cab grounds behind the foot panels in the cab