Ok. First I apologize for the long post. I've read several threads on "no start" issues. None of which match mine. So here I am looking for advice.

A week ago, the truck had run for about 25 minutes and was idling while I went back to hook up a trailer. While I was back there the engine just stopped like someone shut off the key. I looked up but no one was around. I finished what I was doing and go back to the cab. Everything electrical was still on and working fine. I try to start the truck but she won't fire, it just cranked and cranked until the oil pressure gauge moved to normal. It was 60 degrees and sunny out. The truck has 157k miles on her.

I swapped in my spare Black CPS, assuming the one in there failed. It still wouldn't fire. I quickly check the fuel shut off just in case, still no fire.

There is a WTS but I unplugged the ICP sensor, fuel bowl heater and checked the fuse. Still no go. Checked my oil level and HPOP level, both were good. Still no fire. Checked and swapped relays, no fire. I can hear the fuel pump running. Fuel pours from the tube when I open the fuel drain. Still no fire.

I come on here and read a few threads for about 30 minutes then decided to remove my DP Tuner just in case. Went back out and figured I'd give her 1 more try before tearing it apart and the truck fired right up. I shut her down and it restarted perfectly. I quickly moved it to a safe place and shut it back down. Plugged everything back in. Restarted perfectly. I drive it for 45 minutes without a problem.

4 days later, it's 55 degress and sunny, I go to start her up but no fire She just cranks. I unplug the same sensors as last time but this time it doesn't work. This time I check the tin nut on the IPR and electrical connection. All of which are good. Still no fire. I plug everything back in and let her sit. I come back 2 hours later and it fires right up, several times.

TODAY, she won't start like before. I thought the CPS was the Achiles heel but come to find out the IPR is just as vital. What do you guys think I should do? Should I order and replace the IPR, assuming it's my problem? I do not have AE (sadly) or a readily available code scanner to assist. I'm open to any and all suggestions!

 

Where are you located around? If you can wait till the weekend I might be able to meet up with you and bring the AE. You can replace the IPR but I would be interested in some cranking ICP and DC% info.

Riffraff Diesel: Motorcraft IPR

 

I had a similar problem about a month ago. Truck started fine, went into high idol and just quit by itself and cranked but never started. It ended up being the IDM(injector Driver Module) which is located between the inner and outer drivers fender(great spot for it) Its a 5 volt system so I am assuming moisture worked its way in and shorted it. 140k, but I live in MN where theres snow, salt and sand.

Cost around $500.

I also replaced my IPR valve a few weeks ago because it was getting weak. Usually you can tell they are starting it stick when it takes a while to crank over when engine it hot vs. cold start. But they will just quit out of the blues.

I would suggest getting it scanned before spending. My mechanic scanned my truck and found a few other things(like the ipr valve) that were getting weak. The few bucks spent is better than being on the side of the road scratching your head. At least then you have a better idea what could be the problem.

 

Thanks for the fast response!! I'm in Motherlode region of Northern California, near Yosemite.

 

Thanks for the good info! Looks like I may be investing in AE first! I live in the Sierras of NorCal so luckily they don't use salt but moisture is definitely a possibility. I will investigate the IDM a little more.

 

Clay also can hook you up with AE. His response on this thread shows what kind of customer service he has. Great guy! I tried to rep him but I'm in lock down.

 

Thanks! I repped him for you. I'm looking forward to working with Clay!

 

Happy to help where I can, thanks guys.

 

What's really getting me is the intermittent-ness of the issue. If it was the IDM, wouldn't just fail? I can see the IPR sticking, which is why I'm leaning that way.

 

Still a good idea to check the chip and the wiring to the switch (remember key out of the ignition before touching the chip) A loose chip or loose cable will do the same thing, and it's a whole lot cheaper to check.

 

You can also disassemble the IPR, clean it out, and then give it new O-rings if the AE data from Clay shows it to be the IPR. Mine was stuck on 11% so, it would start, but it had no power at all. It's worth a shot... $30-worth of O-rings beats a $200 IPR. At least, that was my thinking when I did mine. There's a PDF around here for that somewhere... I'll see if I can dig it up. But I think you might have found your problem... AE will verify it.

*EDIT* Found it! Here it is: IPR Rebuild

Oh, and not to take from Clay... I support him all the way! I know he'd say the same thing, though... if you can clean it instead of having to buy a new one, then you'll be better off. Plus, at 155K, I have a hard time imagining it'd be worn out. I have 302K on my truck with the same IPR and it's functioning properly.

 

Thanks for that write up!! I ordered AE from Clay yesterday and it should be here tomorrow. I'll run my tests this weekend be able to get a clearer picture of what I need to focus my energy on. I really hope it's something easy like rebuilding an IPR!

In fantasy land, I was hoping someone had the exact same issues and could tell me exactly what to fix... BUT who lives there right?

 

With AE available this will help with diagnostics.

 

Does this contain a magnet? IPR standing for Injector Pressure Regulator?

Mine went bad and it skipped soooo bad because the pressure was supposedly dropping from 1500 lbs to 300 lbs at least thats what the tech said that fixed it.

 

Yes, there is an electro magnet that controls it.