'99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
This is what happend. The thing shut down at the end of an exit ramp so I had it towed. The next day I added 5 gal. of fuel still no start after sevral tries. I changed the fuel filter and was geting 60 psi. Oil level is good and hpop is up to correct level. I then droped the tank to inspect the screen, looks fine. Next I replaced both clips under the valve covers as I have had to do in the past still no luck. Next I replaced the CPS again, used a new factory one (gray).
After not having any luck I did notice the fuel pump on the rail sounded like it was starving at the end of it's cycle with KOEO. So went ahead and replaced that. I tried cranking some but then remembered that I had unpluged the fuel pressure regulator so went to plug that back in. Here is the bad part. When I pluged it back in the key was on and now my fuel pump relay is rapidly clicking. I've checked the fuses, swaped the relays and the batterys are both hot. I have a scanner (cheap one) of course it didn't pull anything before but for the heck of it I tried again because the check engine light now stays on while cranking and the scanner says check signal cable wich tells me I lost power some place? I also noticed that the pressure regulator has some movement not sure if this is normal?
I would gladly take any advice. I know... go get a good scanner but this is more educational since I am a mechanic. I'm just not a diesel one.
...but then remembered that I had unpluged the fuel pressure regulator ...
unplugged the fuel pressure regulator?? Are you talking about the IPR (down below the fuel bowl on the HPOP)? The actual fuel pressure regulator (where the fuel return line connects) doesn't have anything electrical plugged into it.
Clicking relays usually mean low voltage, which could be from bad connections at the battery clamps or elsewhere. I'd double check them. Low voltage could also be the cause of your "check signal cable" on your scanner.
Swapping parts that may not need to be swapped is "educational"??
yea sorry it was the IPR and I plan to double check some things this afternoon
Unplugging the IPR will definitely cause a no-start. It needs voltage to close and let the HP oil pressure build. You can unplug and re-plug it all day long with the key on and it shouldn't affect the PCM. Same for the ICP sensor, although the engine should run with it unplugged.
If it died on you while driving is it possible cps went bad? When mine stopped starting it actually ended up being the 2 diodes in the under hood fuse box keeping power getting to the pcm... good luck!