Hello, I am new to the site. I am sure the issue I am having has been addressed, but no avail in finding the post/answers. I have a 96 F250 7.3 with 259,000 miles. It has run flawlessly until. It sat without starting for approx. 1 month. Problem varies. Sometimes hard cold start/no start when warmed/rough idle-die/ stalls at idle/ run perfect down road (higher RPMS) then stalls. catch sometimes and keeps going. If stalls and quits at higher speeds and idle when its warm it will not restart. Will restart after it sits.
I have changed oil/checked level. Changed fuel filter. Unplugged Fuel filter housing heater after blowing fuse. WTS light is on and glow plugs kicking in. I replaced CPS. Used Q-Tip method on the screen in filter housing.
When it is running and not stalling it runs smoothly and perfectly. Develops power as it should. It is completely stock to best of my knowledge.
Any help would be GREATLY appreciated. Thanks

 

Welcome to fte. I'd be looking at the ipr, at least the orings on it. It could also be sticking. It's on the backside of the high pressure oil pump.

 

I agree with Darin

 

Parts should arrive today. Hopefully will be the fix. Ill post results once completed. Thanks for the help.

 

Inspect the wiring to the IPR closely as well.

 

Ok. Will do.

 

I replaced o-rings on IPR. No start at all now. Added oil in to the pan after cranking. (Assume this is refilling the HPOP resivour?) WTS light is on. Tach does not move at all. Oil pressure gauge does come alive. I have replaced the CPS. It was bought at a "Parts House". Could this be the problem?
This is not my daily driver, and I am slow at working on it. I cleaned all removed sensor plugs with spray contact cleaner. ?tried unhooking CPS and plugged back in. No difference at all. No smoke from exhaust.
Any ideas are greatly appreciated? Now I'm just ready to get it running!!!

 

To fill the HPOP reservoir you simply remove the plug on the top of the reservoir on the drivers side. Mine requires a 1/4 inch drive extension but I have heard that some are Allen head.

The oil level needs to be within 1 inch of the top of the reservoir. Also make sure your tin nut on the IPR is tight. Hand tight plus 1/8 turn is good.

 

It has been reported several times that parts house CPS can be bad out of the box. Motorcraft or International CPS only.

 

Ok. I will replace with one from dealer. I ll post results!!!!!
Thanks

 

I have a NAPA CPS in my tool box, customer replaced a failed cps with it and then spent about 4 hours getting his truck 85 miles to my shop to fix it, he couldn't figure out the problem, 5 minutes replaced cps with motorcraft part and he was gone.

 

One thing I would add that has been mentioned but not explicitly stated is that when you pulled the IPR, that likely drained the HPO res. It will fill (eventually) from the pan, but pulling the plug on the top and filling the res with clean motor oil will get it running a lot sooner. It still takes more cranking than you would think it would to get the HPO system primed and even once it st arts it will likely run kind of funny for a while.

You may, indeed, have a bad CPS, but if it has never smoked or started since you put the new o-rings on the IPR, I would bet you're still trying to prime the HPO system. fill the res up, crank it for 10 seconds or so, then check the level again and let the starter cool for 5 minutes or so. Then crank it again for another 10 seconds, 5 minute break, etc. I've had it take 3 or 4 of those cycles to get the system primed and the engine to start.

 

This is crucial. You either need a different Ford or IH cps or inspect for a broken wire. (I'm assuming your batteries are not just dead causing slow cranking rpms.)

 

UPDATE: I did install the Ford CPS. No start. Checked oil in pan and in the HPO res. Could not find any plugs that I may have missed. Wiring looks good. Batteries are good and have big charger right beside it to keep them charged. Cranked/cooled/rechecked. Repeated several times. Tach is alive. WTS light is on as supposed to be. Sparingly used starting fluid. Got it to run. Will sitting still at 2000-2500 rpms ran briefly then Check Engine light came on and it died. Would not restart. Started checked connections and wiring again. Even pulled fuel filter to recheck things. Guessing with check engine light that it has kicked code. I do not have a reader, looking to get ahold of one to check codes. Will any/standard reader get the codes or does it take specific type?

 

Did you just do the orings on the ipr? No parts store cheap code reader will pull codes here. You need something like AE, scangauge, snapon red brick, etc. Be nice to see that code for sure.