Stock 2002 F350 automatic 2wd with170k on it. A few weeks ago, just out of the blue, my truck decided to not start when cold. No check engine light, no diagnostic codes in Forscan. The engine would spin but no start. After about the third try it fired up like there was neve an issue. I wasn't able to get my scan tool hooked up and connected that time. A week later it did the same thing but with the engine hot, still not able to get the scan tool on it. I was finally able to get Forscan running during a no start yesterday. I did the best I could to follow the diagnostic steps in the TECH Folder. Could yall tell me if it looks like I'm on the right track?

75* ambient temp and good strong batteries
500 miles into a fresh oil change, oil level is good
I show 180rpm cold 215rpm hot while cranking, and no codes so that should mean the CPS is good?
ICP is not throwing a fault code and the truck would not start with it unplugged, so ICP should be good?
ICP during crank was only reading 180psi, well below the 500psi minimum for start, this is why I suspect the IPR. The IPR was replace once around 100k.
Once the truck starts it runs like a beast, no issues at all.

Thanks for any suggestions!

 

It sounds like you are on the right track. Tinnerman nut on the IPR tight? Oil level in the HPOP reservoir up near the top?

 

The nut is hand tight, haven't got a wrench on it yet. I didn't think to check the HPOP reservoir level, ill add it to the list. Thanks

 

I would suspect wiring before the valve my self. That 180 psi is about what you'll see if the IPR is disconnected. It sounds like you're on the right track though. Go through the basics like tun nut tight, ohm the IPR coil, check the level in the hpo reservoir, and open up the harness to inspect for damage.

 

Would bad wiring cause me to read lower than normal ICP but above 180 when the truck is running? The day I was able to pull Forscan data the truck started while I was reading live. I drove it around for a bit but when I pulled in the driveway and let it idle the ICP dropped to 400-425 then the truck died as it decreased lower. Sorry, I forgot to add this in the original post.

 

Helpful to have that data. Still good to check that IPR wiring, but I'd be leaning toward rebuilding the IPR now. Do you know if it was a motorcraft part when it was replaced at 100K? Just thinking it would be good to rebuild an OEM part than a knockoff.

 

The mechanic I use said it was OEM. I ordered an ICP and IPR but also a rebuild kit for the IPR. If I can rebuild it great, I have a spare, but if not at least I’ll have a new one.

 

The IPR valves i controlled with a modulated signal. The PCM is essentially tapping out Morse code repeatedly energizing and de-energizing the circuit. So occasional brief little micro-interruptions would probably go unnoticed for the most part. You might notice it at the pump if at all. Did you happen to have duty cycle % streaming when she started chugging and slowly died? I say check the resistance on the coil and open the loom a bit, less messy and a few less curse words. If you don't find red flags then may be time to pull the IPR and give it a bath.

 

I'm still pretty new to working on these trucks, are you asking about the IPR% ? I will check the IPR resistance and wiring for sure.

Thanks for the suggestions everyone.

 

Hopefully these links will work. This laptop is struggling a little right now downloading the FSM while I insist on being online catching up on the latest gossip.


and

 

Followed up on some of yalls suggestions. The tin nut on the IPR was tight, the HPOP reservoir was full, and the wiring back into the loom looks good. Unfortunately I did not save the data log from when the truck was idling and died so I cant reference it.
Here is a strange question for yall. What brand socket do you use to remove the IPR? I have tried 3 different brands of deep well sockets and can't find one that doesn't bottom out before making contact with the nut. Any help here would be awesome! I'm working 7-12s on graveyards and don't have time to keep running around looking for tools.

 

Mine wasn't "deep" enough either. I chucked it up in the drill press and drilled the 3/8” square a very small smidge bigger for the very tip of the IPR to fit thru it an extra 1/8" or so. The square corners are still there so the socket still fits and has bite tho. It didn't need much modification, just a touch

 

That is the only solution I could come up with as well, just didn’t have time to mess with it. I only lack about a 1/16” for it to work.

 

The Craftsman deep socket in that size used to be deep enough but I don't know if it still is. I can't find mine. I have a deep impact that size that barely does it if I only insert the ratchet after installing the socket on the IPR and ratchet only bites a little but it is enough. IIRC, I have also been able to wriggle it off with a box end wrench but I might have been dreaming on that one. My memory just isn't what it used to be and it didn't start off good.

 

One of the first things i welded was a 1" paddle bit onto the back of a socket making a dedicated ipr wrench. Still have it in the toolbox 15yrs later. Im a carpenter and my welds were bad back then or i would post a photo.