I started throwing codes in the diesel recently, only i didnt know what they were!
As im sure anyone with an OBS 7.3L knows, the OBD-II implementation in these trucks is pretty spotty, which made this one a little frustrating to solve. I started getting a CEL that would appear & disappear and not throw a code (confirmed or pending), but the idle would change when it set. I figured ICP, so pulled the connector and sure enough there was oil in there, so i assumed that was the problem, bought a new OEM one, and slapped it in. It wasnt the problem.
I started digging a little deeper and found in Continuous Memory code P1211, "ICP Higher/Lower Than Desired (engine running)". So now im figuring either my IPR or HPOP is failing. Cant get live data from the PCM with my scanner, so i figured id just yank the IPR out and inspect it.
In case you dont know, removing this required removal of the fuel bowl. Its a fairly daunting task if you havent done it before. The last time this one was out was ~10 years ago, so i was a little rusty on how to do it, but honestly its not too bad.
I immediately noticed something funky going on. It like the silicone boot for the plug turned to goo inside the socket:
The plug for the IPR is on a short harness connected to the fuel bowl. With this removed from the truck, it was easy to inspect. And it looks like weve found a problem!
Well, surely thats our problem!
So i did some research and then called the local Ford dealer. Turns out they had the pigtail in stock, along with all the short fuel hoses you need to reinstall the fuel bowl! So i made a run up there and picked everything up. Fast forward a day, and we're ready for repair!
So here's the replacement pigtail from Ford, p/n 6E7Z-12A690-DA.
It comes in a bag with some crimps and shrink sleeving, but i opted to solder it, and use my own shrink sleeve, as i have adhesive lined
I disassembled and cleaned the IPR while it was out (i should have taken pics, but i was a bit oily at that point), and then reinstalled it. Fuel bowl went back in with all 4 hoses replaced plus the short one for the drain, and i cleaned all the sediment out of the bowl. The HPOP resevoir had been drained so i put about a half quart of new oil in there so it wouldnt try to start dry, and then fired it up!
It did initially pop a CEL, but i attribute that to there being air in the fuel & oil systems. I let it idle for a while, then turned it off/on, and problem solved! Runs great now, and no CEL.