Apparently these things can go bad...never would have guessed it myself but I learned the hard way.

A few days ago I finally got around to re-installing the injectors and new compressor wheel in the F-450 (Simon). All in all things went pretty smooth especially considering it was pretty uncomfortable outside. It was only 104 degrees but the humidity was awful so that made it feel much worse....

At any rate, got it all fired up and drove it around for about 15-20 miles to start working out any air that might be left in the oil passages. Engine ran really well and I parked it for the night. The next morning I took it for a short drive through the neighborhood and it ran nice and smooth so everything was peachy keen. I turn the corner to my home and the engine just shut down like someone threw a switch. While still coasting, I put it in neutral and tried to start and nothing doing. I rolled up to my house and put it in park and tried one more time.

So, I decided to go inside and have a few beers and watch the NASCAR race and get back to the truck later. It's been my experience when something fails right after I was working on a vehicle then it's usually because I did something dumb....so I was racking my brain trying to figure out what I messed up this time. I eventually went back outside and looked around for the obvious and didn't see anything loose or disconnected. Checked the CPS wiring and it looked good but still wouldn't start.

So, I decided to remove my PHP chip just to rule that out as a cause and also bypassed my SPED mod as well. Still wouldn't start. So, I dragged an extension cord out to the curb for my laptop (battery was almost dead) and fired up AE to see what the story was. RPM while cranking was around 250-280 so the CPS was working.....but I changed it anyway. (I don't know why....I'm just stubborn I guess). I noticed that ICP was about 260-280 psi while duty cycle climbed all the way to 85%. So that was a clue that my IPR might be stuck open.

I ran a buzz test and all injectors sounded fine. By this time my volts while cranking were in the 10.75 range so I wanted to make super sure that I didn't have a low voltage issue so I hooked up one of my other trucks with jumper cables and tried again. Engine turned over a little bit faster and ICP was higher but still only in the 360 psi range. Still no start.

So, I figured I needed to pull the IPR, clean it up and that ought to do the trick. Today I stopped by the o-ring store and picked up some -017 and -012 viton o-rings so I can replace them while I have the IPR out. In a giant stroke of luck....Tom (LostMyBeer) called me while I was on the way home and offered up his spare IPR for me to try so I stopped by and picked it up from his home. After a massive monsoon downpour....I was on my way home with a known good working IPR in my hands. I dodged a few downed trees on the way home but I eventually made it in one piece.

I get home and showed the spare IPR to my wife and she said...."Well, what are we waiting for? The rain has lightened up so let's slap that thing in there." So, out we go with two wrenches and a flashlight. I get the electromagnet off and I remembered what Robin (PaysonPSD) recently said on the phone about testing it with an ohm meter. So, I figured "what the heck" and measured the resistance. It started off slow (2 ohms) and began to climb up to 11.3 ish and then back down to 10.3 and then back up again...almost like a yo-yo. I checked the electromagnet that I just picked up from Tom and it held steady around 10.6 ohms.

So, I slipped the magnet onto my existing IPR valve and tightened the nut. To my surprise the engine started! I never would have figured those things can go bad just like that but apparently mine did.

AE and FTE brothers (Robin and Tom) save the day for me.
Thank you both! Much appreciated.

 

Good troubleshooting and repair Greg. And reps to Tom if he shows himself.

 

Glad you got it fixed. Replacing just the electromagnet is a lot cleaner than the entire IPR.

Chris

 

Way to "shake-n-bake" it, Greg.. Now, is the magnet the plug-in harness or if you would've installed a "new" IPR, would that had fixed it also? I suck at electrical troubleshooting.

 

A new IPR would have done the same thing since they come with a new electromagnet as well. The device is basically a two piece item The valve assembly screws directly into the HPOP and has a tail shaft sticking out. The electromagnet slides over that shaft and operates the valve via induction. The electrical connector attaches to the electromagnet.

To remove the IPR, you first use a 3/4" wrench to loosen the tin nut and spacer...then the electromagnet slides off the IPR tail shaft. There is no fluid loss at this point. The oil will drain out if the valve itself is removed (which I didn't have to do, so I was lucky.) If I needed to remove the valve, then a 1 1/8" box end wrench will finish do the job (or a deep well impact socket since it's longer than a normal socket...). Unscrewing the valve will allow oil to drain into the engine valley so be prepared with rags etc.

Here is the best pic I have at the moment. I'll take another photo of the exploded pieces.

EDIT: In the photo below...I believe the nut may be on backwards. The concave side goes towards the spacer I believe....

 

Awesome !! That monsoon was nasty. Blew down the neighbors tree on to their car. The tree just happened to be behind Gregs truck. We didn't even know it was down until I saw a car drive around it. Pulled the tree off the car with truck...nice and easy....lol

 

Thanks again for the loaner...I tried to rep but I am in jail...(again).

 

Got him for ya Greg

 

That sounds exactly like what I'm dealing with right now shake-n-bake. My truck just died while going home Sunday night & I have been tearing it apart trying to figure it out. Only owned the truck for a few months & its my first diesel so it was slow going but with the help of some great people on here I have been able to narrow it down to the HPOP or IPR. Could u maybe explain in detail how u test the electromagnet so I can pull mine off & check it? Also is this a piece that can be purchased separately or do I need to buy the whole IPR? Thanks!

 

Greg,

Would you VERY-carefully examine the solder joints?

I wonder if long-term vibration is starting to cause erratic connections, and this will become more common as time goes on.

I'd hate to think of the use of a fine-tipped soldering iron as some kind of routine preventive maintenance procedure.

Pop

 

Kinda what I was thinking when I replied to your other thread. The IPR coil resistance should be between 5 and 20 ohms according to the Ford workshop manual. I attached a good IPR write-up.

Sorry if I hijacked the original thread.

Chris

 

That's a great write up Chris, thanks. That's probably the first thing I will do before spending $170 on a new one. Do u know if a person can buy just the electromagnet part if it goes bad?

 

Just remove the magnet portion from the vehicle and use a multi-meter to test the resistance between the two pins. You can do it on the truck if you like but it will be very hard to see what you are doing. I am told that you want to see a STEADY ohm reading with very little variations (0.1 ohms or less). My original part was all over the place when I was taking the reading...


10-4. I will post what I find with pics if practical.

No hijack at all....thanks so much for the info.
I wasn't sure what the acceptable spec was but Robin said his measured in the 10-6 to 10-8 range I believe...

 

I am trying to find the answer to that question as well.......

 

Does anyone have a pic of the ipr coil/magnet? It looks like it could be the same as a lot of the ones on hyd valves. If so, I bought a good used one the other week for $12 so they are not terribly expensive. I am not with my truck right now or I would go look. The freightliner with the cummins in it will not give me the answer.