You can pressure up through the ICP only if you still have the check valve fittings in your HPOP if not it will just bleed the air back through the HPOP.

 

I'm resigned to pulling the covers off at this point but will try the compressed air test and will also look again at the fuel filter prior to doing so. Talked to Clay at Riff Raff and he still thinks it may be air in the system that hasn't worked it's way out since it hasn't been driven, just idled. Pulling covers won't take that long. Might as well just do it.

Thanks for all of the suggestions. Much appreciated.

 

Replaced the pigtail on the IPR and then cranked the truck. After about 5 seconds of cranking it fired and idled. Still had the same stumble as though not all injectors were working but not bad. Clay thinks there still may be air in the system causing that issue. ICP and ICP Duty cycle acted normally during cranking. Both rose to fairly high values then the engine started after about 5-7 seconds of cranking. At idle, the ICP dropped to about 500 with a duty cycle of 17%. Oil temp was 85F. Continued to idle with normal values in all areas. As it warmed, I gave it a little bit of throttle and let it drop to idle. While cold, it didn't seem to falter. After it warmed a bit, it seemed like it was going to die again at idle.

After the engine warmed, I killed and attempted to re-start. Oil temp of 123F. Once again my ICP only reached 270psi with a high duty cycle and no start. I'm going to cautiously believe that it's the IPR. Oil is new and is Rotella 15-40 semi-synthetic. Surely the oil would not thin enough to keep it from starting after warm. I hope it's the IPR.

Also, the heater core gave up today. The diesel in the coolant did a number on the radiator and heater core. After it's all running well, I'll replace those parts along with the water pump and all hoses.

 

I'll give you a big thumbs up for effort and not giving up. I think you are zeroing in on the problem. Once the oil thins a bit due to heat it's leaking somewhere. Could be the IPR or could be one or more of the injectors o-rings damaged. HPOP is a very high pressure but low volume pump. I can see where when the engine is started cold and running at higher RPM's than cranking it keeps running, then restart when hot it can't keep up at cranking RPM.

 

Did you say you had an IPR on the way?

My gut is telling me the IPR, but my gut tells me to do a lot of things that don't work out.

 

Yes, I just ordered one since the old was original with 240K miles. I'm not absolutely certain that it's going to cure it but I figured it would be good to have a new one in there for the remainder of it's life. IPR arrives late today. I'll put it in tomorrow and see what happens. If no go after that, the valve covers come off. Not even going to attempt the compressed air test in the oil rails. I would think it has to be injector related if not the IPR. Fingers crossed.

 

Tell me how diesel gets in the heater core? I don't see how this could happen. If it's oil maybe the oil cooler on the engine. Sounds like o-rings to me. That would tell you why there's no IPR pressure and high duty cycle. Just my two cents. And being that's where the work was done, well that's my guest. God bless
Now if o-rings go bad, and heater is on, then you can get diesel in the heater core. The fact that the heater core went out doesn't put diesel in the core or system.

 

Originally, I pulled all the injectors in order to change the Brass injector cups that sit in the heads. They or the O-Rings on the injectors were bad and dumping fuel into the coolant. Common issue at 240k. I decided to put in new pigtails, rebuilt Full Force Injectors and glow plugs while in there.

 

Oh, forgot to mention earlier that I did look k at the fuel in the bowl. Looks like clean, pure diesel but I did change the oil so it's not so easy to tell if oil is getting in there. I'm still trying to be optimistic at this point that my injector and cup job was good. It's been an experience, that's for certain.

 

That's what I get for reading late in the thread and not going back to the start.

 

No worries! It's been a long journey!

 

My daughter lives in Denton. Her boyfriend drives a Power Stroke and owns a shop around Denton.

I will contact her and find out about the shop. Will PM you the name and no. of the shop.

 

I'd like to change that to not an unheard of issue. I've had 4 7.3's that went over 250k miles with no cup or o-ring issues. I've personally seen and known of many others that didn't have those issued either.

On my 02, I even replaced the injectors at 300k because everyone, including a well known injector rebuilder said the injectors should have failed by now or start failing in the near future. I saw absolutely 0 change with brand new alliant injectors going in compared to my "worn out" old ones.

Those injectors now have over 260k miles on them with the same o-rings and the cups are still factory original with 560k plus on them.

So your situation is not unheard of by any means, but not necessarily automatic.

And the no restart after getting hot points to either IPR or leaking o-ring under the valve covers. One is cheap, but takes a lot more labor. The other is expensive but relatively easy.

Keep us posted.

 

Wow, that's pretty good service from those trucks! I've known 2 others that had the same issue right at 240k. I was told by a diesel mechanic that the 7.3's had that issue pretty much at 240k. I'd say you had exceptional service out of those trucks. Mine was a service truck in Dallas area with hot as hell Summers so I'm pretty happy with my 240k and no major issues!

 

Philn, any updates since the new IPR was installed?