Didn't get to check the UVCH today. We figured out what was wrong with Tyler's green truck, and then did a few more things to his cc. I did plug the Edge in and checked for codes, and the only one was from the EBPV delete, and the Edge doesn't read the ICP. The truck seemed to run ok today. I felt the vibration around the 1600-1700 rpm range at times, but no bad missing like yesterday. Still has the rough and surging idle though. Tomorrow when I get home from work, I'm gonna check the UVCH and I need to get the hose made tomorrow for the HPO gauge I have so I can check it that way I guess.

 

I checked the plugs on the UVCH and there are no burnt pins. I pulled each plug while the truck was running, and of course it made a drastic difference. I haven't pulled the valve covers and inspected underneath though. Here is a video of what the idle is like. I unplugged the ICP and it smooths out, you can't really hear it in the video, but you can watch the tach. I then plugged the ICP back up.


<iframe width="420" height="315" src="http://www.youtube.com/embed/SEn5F-UrEmc?rel=0" frameborder="0" allowfullscreen></iframe>

 

I took my homemade HPX off and hooked a 5000 psi gauge in the middle port on the pass. side head. At idle it dances right around 600 psi. If I slowly bring the rpms up, the psi doesn't change until I get it over 1500 rpm. At 2000 rpm, psi was at about 800 psi. At about 3500 rpm it peaked at 2700 psi. What does the psi not raising until passed 1500 rpm mean? That is about the rpm I feel the vibration while driving. Is my IPR sticking? Some body help!

 

That would be a good guess, sticking IPR. I'll go see what mine does.

 

Mine was the same as your reporting. I thought it should be higher too, just takes a load on it to get the pressure up I guess. I made a homemade one once long enough to stick out the hood at the crowl and tied the hood down and went for a ride.

 

Thanks for looking Glenn. That's what I did with the gauge, stuck it out under the hood on the cowl so I could see it from the cab. Well, I guess I can rule that out. When I bring the rpms up slowly and hold it at 1500-1600 rpms it stumbles slightly as long as I hold it there. Like I said earlier, that's the rpm where I feel the slight vibration while driving. I replaced the injector o-rings and glow plugs when I got this truck, could have blown an o-ring or could it be a bad injector? I haven't ruled out the UVCH, cause I did buy them at Napa.

 

Didn't you say it ran real bad at the start of the thread? Intermittent right, not all the time? If its only a slight vibration all the time, it could be an injector. I don't think its injector orings with what you said.

 

Yeah, Monday on the way to get Tyler's driveshafts it started missing real bad, like I lost a few injectors. It shook the whole truck. But after it sat and idled for 10-15 minutes, it didn't do that anymore, just continued to do what it's been doing with the vibration at 1500-1600 rpm and the surging idle. My buddy who owns the shop that fixed the wife's car from the deer has a '97 PSD. He said his was doing the same thing. He has a Nemesis scanner and he buzzed the injectors and they buzzed fine, but when he did a cylinder contribution test, it said #4 injector was bad. I might run it up to him tomorrow after work and see if he will put mine on his scanner.

 

I think you need to pull the VC's. I would pull them, then start the truck and look at the oil spitting from each injector's spill port. If you have on that is spilling less, or not at all, you know where to start looking. It still sounds like either an HPO issue or a UVCWH to me. You could always put the HPO gauge out the cowl and take it for a spin. That would pretty much determine whether it was a HPO issue or not. Unplugging the UVCWH's from the outside may mask the issue since you're disconnecting 2 cylinders at a time. If you get under the covers, you can disconnect them individually and see whether any one individually makes a difference.

 

Ok, I'm sure now it's the UVCH. The truck ran fine to work this morning, and on the way home, I went by my buddies shop and put it on his scanner(OTC Nemysis) The injectors buzzed fine, and when we ran the cylinder contribution test, it started acting up like it did the other day. I started pulling the VC plug one at a time and found it.

My other concern is the surging idle. I guess we'll see if the UVCH fixes that. While we had it on the scanner I noted the IPR duty cycle %....

At idle: 12% @ .93v
At 2500 rpm: 22% @ 1.90v
Revving it up over 3000 rpm it was going up to 33%

I looked at the pulse width of the injectors, but I wrote all this on my hand with an ink pen, and it got smeared, and I don't remember what it was.

I don't know enough about this info to know if it's right or not, so can anyone tell me if it sounds right?

 

That was my problem yesterday Nate, unplugging the UVCH plugs while it wasn't acting up, I couldn't determine anything. This evening, it was running like crap, so I got it while it was doing it. When I unplugged the one to #6 and #8 cylinders, It didn't change.

 

I pulled the VC and I can't find anything wrong with the harness. Visually it looks fine, nothing burnt or melted, and I checked it with a meter, and it checked out good.

 

I don't know what the duty cycle is without a load on it, so I'm not much help there. Maybe hook everything up and start it with the vc off on that side and see if the injectors spill equal amounts of oil.

Sure sounds like a uvch problem, but I don't know what to else to say right now. I'll put my tiny mind to work and see if I come up with something though!

 

Bill, I've got a VC gasket I can send you to try. It's an original OEM (as far as I know) with a slightly burnt GP pin, but I'll overnight it if it helps to trouble shoot.

 

Crank it with out the VC's and stray wiggling the plugs and wires