Ok, last year this problem happened when I went out my annual trip. The problem had not re-occurred until again this year when I hook on to my 7500lb trailer and put my camper on. It seems that I can sometimes drive for 100's of KM's without an issue, but then when all is well... I get a pulsing (sounds like boost releasing) noise and the power level falls flat on its face. If I stay on it and work it hard, this progresses into what appears to be a very bad miss.

I stopped by the dealership and he replaced the ICP as my old one was leaking. This got me about 200K down the road thinking all was good, and boom same issue again. I camped for the night, started the truck in the morning and it sounded like it was running on 5 cyls. I disconnected and reconnected (and cleaned) the UVCW connectors and all seemed to be ok. (For a while).


I tried the following things with no improvement:
Disconnected MAP
Disconncted ATS
Disconnected EBS
Replaced Fuel Filter
Replaced Air Filter
Put a litre of ATF in fuel
Disconnected Red Hose to Waste Gate


I am getting the Low Boost pressure failure code and the EBS code (Last year I had a CYL 7 Injector failure code that has not returned)

I am 1500K from home and would like to make it back. The strange thing is that sometimes everything is good for 100k or more, then all of a sudden it falls flat on its face and I am climbing hills in 1st or 2nd gear (standard).

On my trip, I removed the camper and trailer drove for almost 3000k without a hickup. Not sure why this only occurs under Sever duty conditions. And why I can sometmes drive for 100's of Kms before it starts.

Once the problem starts I can't seem to shake it, I try everything and it will be ok for a hill or 2 and then returns with vengence.

Help! Are there any more sensors I can disconnect to narrow this down?

My Moose and Bear are in the trailer and getting warmer by the min... Need to get home...

Help!

 

Oil level and condition? The pulsing sound you hear is most likely turbo surge, while not the best thing, it is not going to cause your problems. You really need to have your codes checked, sounds to me like you have a failing IPR, or maybe just a dirty one.

 

sounds like turbo surge..and defueling cause you going over 22 lb of boost...does it sound like a pressure cooker doing its thing??
if it is surge a wicked wheel will help or ATS houseing will cure... this mostly happens on a chipped truck or stock truck while towing...till you do one or the other all you can do is let off the go peddle a little....or down shift out of OD before you get to that point where it surges..

 

Surge should not cause it to fall flat on it's face and is only temporary till the throttle is released. It does sound like a boost issue, perhaps a wastegate problem.

Could also be a fuel delivery issue of some sort. I have read here that ATF is a no-no due to additives.

I might also suggest getting ice for the game!!

 

Well, this is definately not just turbo surge. I start off on the hill with 22+ PSI of boost, then gradually it falls down to between 13-17psi. The same things happen on hills that I should be able to sail up and over without a problem... I downshift a gear from 6th to 5th and it shas 22+psi of boost and then same thing gradually works it way down to 13-17psi.
If I continue to beat on it up the hill down shift and push, it will result in 2nd gear (or fist in some cases) and barely getting up the little or big hill. I can only make this happen with a very heavy load (7500lb trailer and camper). I have not been able to make this happen empty. I would almost say that this is a fuel loss situation because it results in cyls missing to the point where it will barely run.
one thing that stands out is the "Push Pump". I had my buddy turn the key on while I looked in the filter bowl. The fuel kinda dribbled in. There didn't appear to be much volume. Should this "shoot" into the bowl? Could I be running out of fuel and then getting air in the fuel rail resulting in missing? There are no codes coming in that I can't explain other than the EBV sensor, but from what I have read this will only result in reduced power, not missing of cyls etc...
The UVC wiring I think would result in a more regular issue, not something intermitant like this and not just under HEAVY load.
If this were a gas engine I would say its timing or fuel loss (but its not a gas engine). Any suggestions anyone?

Oh ya, one more thing, when I made it to the final 50k of my trip, (I was able to find the sweet spot that didn't completely incapacitate the truck for most of the trip, I was driving flat roads and trying to get the the ferry. All of a sudden the truck (no hills now) just started missing and farting and even died a couple of times (Like the time when I accidentally left the filter drain open and drove away). It did this for about 5kms at about 20kms/hr down the highway, then again all was ok.

 

I'm kind of thinking it's a fuel issue too. How clean was your fuel filter? Weak fuel pump, debris caught in the FPR, partially clogged screens inside the fuel tank? We've seen several problems with clogged screens lately, and the problems always seem to run in groups. (or is that just me seeing it that way)

 

You running bio? From what I hear/read (have not used it yet myself) it will clean the gunk out of the tank, and can clog the screen in the tank. Maybe under a heavy load you are outrunning the fuel supply coming from the tank??!!??

 

A sticking IPR can cause intermittent symptoms similar to yours. I agree with others that it sounds like a fuel issue. I would focus on fuel delivery, both the high pressure oil and the fuel delivery itself. I had an intermittent IPR problem that only seemed to occur when I was towing 8000 lbs or more. When towing my little 12ft 4200lb. trailer she would run great, but when I hooked up my
16ft. weighing between 8200-8600lbs. I had symptoms similar to yours. I first replaced the IPR o-rings and saw a feeble improvement. When I replaced the IPR, all was well again.

If there's anyway you can monitor the data stream, you can see if the IPR duty cycle is too high. If it is the IPR o-rings are a cheap place to start. Until you can analyze the data, you can't be certain. It gets old, and pricey throwing parts at these engines.

good luck to you, and please post back with your solution, which I hope comes quickly for you.

Austin

 

Fuel should come in much faster than that. You can open your drain valve and turn key on and it should produce a good steady stream. And yes, if you are running out of fuel or have very low pressure, it will cause poor running, coughing, sputtering, ect. Need to find why, pump going bad, fuel screen in tank clogged, low fuel in tank.

 

I will look into the fuel delivery situation over the next couple of days and definately post back... Keep you all updated, I appreciate your time in helping me with this one...

 

Update. So I haven't had a chance to even touch my truck since my last post, but I thought I would let everyone know that the trouble has progressed to effect normal every day driving. I experienced the same problem in an empty load situation, so this re-afferms my theory that this is a fuel deliver problem. There is a noticable loss of power under normal driving conditions now, I will be checking my fuel pump/pickup issues this coming week and report back.

 

Well, I looked into my filter bowl and saw that the fuel wasn't coming in very quickly. So, I hooked up a hose to the tank side of my lift pump and placed it into a bucket of clean fuel, checked in the filter bowl again, however I was just getting lots of air at this point.
I figured I had nothing to loose and dropped the tank out, I had to cut off the hoses (didn't have the right tool for fuel lines) and replaced with fuel hose. Check the pickup, the cleanlyness of the tank etc... etc... etc... All seemed to check out ok. I put it all back together, looked in the filter bowl and now it comes in there nice and hard. Not sure what the problem was, or what I did to fix it, but now all seems to be working smooth. I have a very noticable increase in power, and suspect that my ongoing problem under load will now be fixed.
Anyone have any idea why this worked? and what the problem might have been? The screen on the pickup was looking good, I reached around in the tank (still had about 1/4 tank of fuel in it) and felt no grit, no junk, nothing.
But, it seems to have fixed my problem.

Ideas?