I had a bunch of down time from knee surgery and needed to replace the oil cooler. All OEM parts were used except for egr cooler being sinister that came new but hadn't installed. Truck ran fine but deltas were getting 20-25 while unloaded. I have replaced some of the pigtails when needed, but having it apart for the other work. I looked very close at the main engine harness which was oil soaked and carefully unwrapped it checking for any problems. A couple of the pigtails were replaced and all re wrapped with abrasive type tape. All connections looked good but hit the key and no start just cranking over. Did it a couple more times and it fires but rough. Trying again and it's sounding new. Shut off re try no start. I didn't touch anything other than egr cooler oil cooler and wiring harnesy

Koeo. Koer
Ipr 14.8. 33.4
Icp. 2. 950
Icv .23. 1.09-1.43 fluctuated
Ficm in 12.9v cranking 48.5 and 48.5 running.
Batteries are fully charged with trickle chargers
13.9 at batteries
Fuel bowl is 57 then 55 if it starts.
Every so often it's showing ficm sync 1 and sync 1 and starts and runs smoothly. It's non consistent. I've checked continuity and get from pcm pins 2ohms resistance. I'm thinking wiring harness but really cleaned it and checked it throughly. I've hit the wall. Any idea how to track down my issue would be great. Thanks

 

Clean the IPR screen. It's probably full of air and will take a bit of run time to clear. Keep batteries charged and fire it again.

It needs to be cam and crank sync 1 for FICM sync to be 1... probably your issue. Wiggle those sensors connections.

 

I inspected and cleaned it before reassembly, and I've had someone cranking it over while wiggling the cam and crank wires, Multiple times. Checking that everything is clean. If I'm getting 1200 while cranking and 850 if it gets sync do you think the ipr would still need cleaned?

 

YES... any time you replace the pump or do oil cooler work, you knock debris loose and it inevitably ends up in the screen... why its fluctuating and showing a higher number.

Start there, then we'll see what's next.

 

You could of cleaned the IPR spotless before reassembly, but, if one piece of dirt gets into the oil valley once you remove the cooler that can jam up the IPR......

Very common when this job is done, lint from rags/paper towels can also clogg it as well.

I like to use as many cans of brake cleaner before remove the oil cooler housing, I leave the turbo drain in place so nothing gets into that, and spray away. Then use a air compressor and spray the crap out of that area before removing the oil cooler housing.

They make a special socket to remove the IPR without having to remove the turbo.

 

I'll do that as soon as I get home from work and post my results. Thanks.

 

An oil cooler R and R on a 6.0 should rank right up there with open heart surgery in terms of cleanliness. Can't hardly get things clean enough, it's a royal PITA but worth it.

 

I did clean it with a toothbrush, then vacuum the loose stuff, then brake clean, vacuum, then shop air. I inspected the ipr but replaced it right after. When I pulled the oil cooler I didn't remove the screen and cleaned all oil and wiped out with lint free rags. I only changed out the screen when I was replacing the cooler. So I picked up the tool and removed the ipr valve. It's as clean as when I put it in. I don't think I was clear in my first post. When saying it was at 1500 then 850. 1500 while cranking and then if it did start it would idle at 850. Is there any reason to leave it apart or put it back together to troubleshoot more?

 

If the screens clean and there are no rips, put it back together.

 

I'll wrap it back up. What would you check next?

 

When it doesn't start, are you getting any sync? Or any fuel pulse width? Program fuel pulse width into the gauge, when everything's right it will command fuel.

Electrical issues are hard to find. Watch cam and crank sync, fuel pulse and icpv.

 

From reading this post several times the only thing that is suspect to me is the pigtails you replaced while doing cooler. If it was me I would redo those connections. Something funny about 1500 psi during crank (150 rpm) and 850 psi at idle (550 -650 rpm)

Edit: I would like to add what WarsonR stated would be what I would have done first. You are trying to elimate problems one at a time.

 

I'm putting it back together now, I'll program it with the fpw and try and start it. I only get the sync when it starts. Should have it in a little bit.

 

All back together and took a few tries and it started, after it started I had both sync and ficm sync. The icpv was between 1.15-1.27v and fpw would run between 960-1248, and icp would be about 400 lbs under in pressure. It would rise and fall in construction with fpw. I don't know if that's how it's supposed to be. The one thing I noticed was it wouldn't start right back up. It would take multiple tries. I'm wondering about fuel maybe, because the fuel filter is a mechanical one that's on the test port and it fluctuates back and forth between 50-55 lbs. I also hear the injectors are louder than normal, more than I would feel comfortable with leaving it running very long but I don't really know how loud is bad. Then it will quiet down and idle fine for a bit and continues to fluctuate. I first thought it was doing it because it was having such a hard time starting. But when it's turning over it's not sounding like it's trying, it just fires and goes into idle. I'm wondering if the sync doesn't trigger until it starts and not just before. Seems like it's all at once but Maybe the sync won't show until it starts. I don't know just what I thought.

 

the odd icp numbers and the loud rough idle sound like when my icp and or icp pigtail where starting to crap out.