Well, maybe it's the damn IPR after all? At WOT, the duty cycle maxes out at 35% (It won't go higher) and I never see the ICP above 2300.

I'm going to dead-head the pump and see what's up there. But I'll check the harness for resistance from IDM to injector first.

Hah! Sounds like my truck! Mine will occasionally go above those pressures, but it rarely sees 2500 PSI. I've seen it spike the IPR to 45% or so just once and if the truck that good all the time I would be thrilled. I've changed literally every sensor on the engine to try and diagnose my issue. Hopefully you will have better luck than I am having. I think mine needs either a new HPOP or Injectors and since you have already done the injectors I'm thinking more and more that it may be the pump.

By the way, if you end up needing lifters or pushrods and don't mind used, I can hook you up with whatever you need for the price of the shipping. It'll take them a few days to get from OH to WA though. If you're in a hurry or want new parts, Riffraff Diesel would be your best bet since they're a lot closer to you and have the best prices and customer service on this kind of thing.

Well, since the compression came back mostly good, I pulled the IPR. One of the seals is bad but I'm not sure if I did that during disassembly or not.

Edit: Nevermind, apparently that seal is supposed to be split:

http://www.riffraffdiesel.com/ipr-complete-re-seal-kit/

I've learned two lessons that I'd like to share:

1) Even if your pin-out resistance checks come back fine between the IDM plug and the injectors, the truck still won't run if you don't plug it back in.

2) If you see an o-ring sitting in the valley when you have the IPR out, you should probably recover it. Then when you start the truck up and you leak several gallons of fuel in just a few minutes, you'll have it handy to put it back on the fuel pressure regulator where it belongs. If you don't recover said o-ring, guess what, you get to pull the bowl again.

-Matt

Lol, life lessons... Sometimes the best lessons are the hardest ones.

I was thinking he bought the truck with the miss/smoke/low power issues, but I just looked back through this thread and that isn't apparent to me now. I must have mixed something else up with this thread.

I did buy the truck with this issue. I paid $1500 for this cherry 4x4 standard cab it and it came with a chord of firewood. The engine has fantastic compression.

Now if I could only figure out what's wrong.

Oil Aeration, Fuel Aeration, IDM.

That is the path I'm heading down now. I don't know what else it could be, unless the o-rings are indeed bad, or the injectors I got from Rosewood are bad.

Then I stand by what I said about injector wires being crossed where they're spliced with the new pigtail harnesses. Its free to check, it just takes time.

I'd agree that the wiring, IDM and maybe even the PCM would be the ones to start with.

I already checked the wiring, it is not crossed or shorted.

I'll get around to throwing another IDM on it when I can find one.

Thanks
-Matt

There is definitely a hole in the rubber line for the return line.

It looks like all of the hoses going to this bowl on the low pressure side are just run-of-the-mill black fuel hoses with screw-type clamps. I could replace all of them with more of the same and maybe fix an air leak. Who knows?

You can use SR9? fuel injection hose. The blue factory stuff is rated for a lot more heat, but others have used the fuel injection hose.

Well I pulled the fuel bowl out and replaced all of the hoses. I used transmission oil cooler hose. The old hoses were all bulged and in very bad shape.

It didn't make a difference.

So I found a guy parting out a '99 powerstroke, drove an hour and a half to drink beer with him while I pulled the IDM out of his truck and plugged it into mine, revved it once and said "I'll take it!". I gave him $100 and my old IDM so that he can move his parts truck around.

It is night and day. I am in a very good mood.

Thank you everyone!

So wait, the IDM fixed it then?