My IPR is maxing out at 84 as I drive. I haven't stopped yet and don't know if it's going to start again. What could be the problem? Maybe just the screen on the valve?

 

Yep or a big leak or a dying pump.

 

We chatted today and I found out it's a 2006. So that puts the better pump in it but gives
him the STC along with stand pipes and dummy plugs. He said that he would so an air
test first thing and I added that pulling the OPR and checking the screen would be a good
idea. That will give him some things to start on after an air test.

 

Hey guys, thanks for the help and, Sean, for the phone time. Here's the story:

Last summer, the truck went through a few weeks when it was taking a long crank first thing in the morning to fire. I never did anything, and it went away. Then, over the winter, it started that again. Always runs and starts fine afterwards. We're talking about, at least, 45000 miles on it in the last year, so I don't know if that means anything.

But anyway, this week I'm pulling about 5000lbs to Austin. At one point I felt a lack of power, but otherwise cruising along about 60 when I look at my ScanGauge and see the IPR pegged at 84. For the next 100 miles or so, through some low hills and a couple of stops, I got little power, it's always pegged at 84 unless I'm coasting downhill, but it's still going and I need to get the load off my trailer. That's when I posted. I figured it's a loss of high pressure oil or the IPR screen, and figured if I turned it off, it might not start again.

Then, going up the last and steepest, but small, hill, the one I'm worried about making it up. Halfway up, the truck kinda hiccups as I'm trying to get it to downshift, and it catches a gear and climbs up the hill. I look at the IPR and it's back in the 60s. I get to level ground, and from the IRP gauge, it seems to be running normal. Hard to tell pulling the trailer, and I wasn't going to push it to see. Instead, I rode it all the way to Dallas, and it drove fine. After I unloaded my trailer, I could push it a little more, and it ran fine. Next morning, it started up with the usual long crank, I loaded up with about 7000lbs and drove back to Houston just fine.

Last bit of info, when it was maxxing at 84, it idled about 32. Then, when it first started acting normal again, it was still idling at 28, then down to 26. Today, fired up again as usual, and idles at 23-24 - completely normal again. Runs great.

So, is there any of the suspect leak sources - standpipes, dummy plugs, etc. - that match up with those symptoms? Or that can leak, then stop leaking?

 

Oh how I hate guessing. I think at this point I would put some air into it and see if you have any leaks in the HPOP.
Do one cold first thing and then do it after you have it up to temp. Use your mechanics stethoscope (the one with the long rod on it)
so that you can pinpoint around the HPOP cover. Also if you don;t have a stethoscope I have found that a 18" 1/2" PVC pipe works
wonders as a sound pinpointing tool. You could even use a cardboard tube for towels. If the heaviest air sounds come from the oil fill
or the CCV hole then I would look at the stand pipes and dummy plug.

 

Yeah, that is the plan. This is my first experience is a high pressure leak. I just thought it was odd the way it self-healed, and now drives fine. Is that common?

 

Not that I have heard of.
But you also need to be looking at the ICP numbers also to see.
The high IPR is the demand and the ICP would be the value that
the system is getting.If you happen to go out and drive and it acts
up pop the hood and disconnect the ICP sensor and see what it does.

 

LOL, you're wanting me to actually understand what the engine is doing rather than just reading a gauge and plugging the number into my what-could-be-wrong form. I'm the liberal arts major who avoided anything to do with science and math. But, that sounds promising. So, when it does this again, and I jump out and unplug the ICP and it a) dies, b) runs the same, or c) runs differently, I know that a) it's not ____________, b) it's not _____________, and c) IT'S THE ____________________!!!! If you'll help me fill in the blanks, I can add this to my form, lol.

Here are my Bonehead guesses: a - I don't guess this would happen. Maybe it would never start, but it should keep running. b - maybe a bad ICP, or a air leak around it? c - it quits erroneously demanding more fuel, so the IPR defaults to some normal range, but I don't have a clue whether the engine would run better or worse or whatever, and whatever that would mean. In fairness, I've already had my morning bowl.