Surging returns after only 100 miles

[06kngrnch84]

So I was having some surging problems last week. Started slow then got worse. This weekend I took out my EBP sensor and cleaned it, took my turbo off and cleaned it, for the second time in two months, and took the vgt solenoid out and inspected it, it seem to be fine. Truck ran great yesterday, plenty power and turbo spooled and built boost great, today on my way to work, its starting again, not very bad but the same as it started the first time. Am I lookin at a new turbo here or does anybody have any other ideas?

Thanks in advance

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[justa03]

I have seen dirty IPR's cause surging issues at idle. Wouldnt be a bad idea to pull it out and see what the screen looks like.

[06kngrnch84]

Originally Posted by justa03

I have seen dirty IPR's cause surging issues at idle. Wouldnt be a bad idea to pull it out and see what the screen looks like.

Just replaced the screen about a month ago when I upgraded the stc fitting. And sorry I didn't specify, the surging is during acceleration and while cruising, it idles just fine

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[justa03]

Fuel pressure issue maybe? I generally instead of cleaning out the EBP tube I install the new sensor with the new tube, avoids comebacks. Are you certian the turbo is sticking or just guessing at it and took it and cleaned it? I guess I cant really see one sticking that bad that quick if your using the truck the way it should be. Are the vanes and unison ring ok? Ive seen vanes that were wore bad from being stuck. The guide that goes into the uinison ring is usually wore down bad if that happens though.

[06kngrnch84]

No I'm not sure the turbo is sticking, I guess I was just tryin to rule out possibilities. The turbo and all its parts seemed to be fine, far as I could tell, everything moved freely. I mean I know something is causing it to surge, I can hear it spoiling up and down constantly during driving and my boost gauge fluctuates. I do notice that when the dash boost gauge goes up to or above 20 that the boost reading on my scangauge goes to a negative number, usually around the -13.5 range, but at the same time it sounds like the turbo is on with dash gauge, not sure that this means anything. Fuel pressure could cause the turbo surging without any other driveability issues? Did the blue spring upgrade about a month ago just for preventive maintenance, had the pressure checked at a shop after that and they said it was good, can't remember the numbers off the top of my head. Just seems strange to me, I cleaned the turbo about a month ago when I done all the work in my Sig, and everything was great til last week, then cleaned it again, just for good measure, and it ran great for a day, now its doin it again? I don't know, I'm lost on this one. Thanks for the help so far and keep the ideas coming.

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[justa03]

Ok so just the turbo is surging and the whole truck isnt? What i was getting at is the turbo can only do what is supplied to it so if the motor itself is surging that would make it seem like the turbo is. But there is no way you can get a - pressure reading(or vacuum) on a diesel. Is the truck lacking any power? What are your boost readings at WOT? Whats your EBP at cruise and at idle? It is possible that the turbo could be stuck but I just cant see it if you say everything is ok inside it unless youve got a VGT solenoid issue. Does it only surge at curising speeds? When it does surge if you accelerate or decel does it come out of it?

[06kngrnch84]

Originally Posted by justa03

Ok so just the turbo is surging and the whole truck isnt? What i was getting at is the turbo can only do what is supplied to it so if the motor itself is surging that would make it seem like the turbo is. But there is no way you can get a - pressure reading(or vacuum) on a diesel. Is the truck lacking any power? What are your boost readings at WOT? Whats your EBP at cruise and at idle? It is possible that the turbo could be stuck but I just cant see it if you say everything is ok inside it unless youve got a VGT solenoid issue. Does it only surge at curising speeds? When it does surge if you accelerate or decel does it come out of it?

No I don't notice the truck surging. It lacks power when first taking off, put the pedal down, its real sluggish but then the turbo spools up fast and away I go. The surging goes all through acceleration and a cruising speed, doesn't seem to get any better, but if my foot isn't on the pedal or the cruise isn't set I don't notice a surge. Boost at WOT is reading around the 22 area on my dash gauge. EBP at idle is 19.9. I'll get the cruising EBP in a bit. VGT at idle is 71. Will repost with cruising readings on those.

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[06kngrnch84]

Ok, just went for a drive. What I noticed is that the surging wasn't nearly as bad, still some though, I also noticed when it would do it last week that it seemed to be worse in the mornings when the outside temp was colder and it took longer to reach operating temp, that said I still don't drive my truck until ECT is 150 or higher, then I take it easy til its gets up to temp, not really sure what this would have to do with it. Also cruising at 75 mph, as long as I was on flat land or going down hill I had no surge, when I started goin up hill and during acceleration and the rpm's jump up to keep the cruise speed is when it would surge, needle goes up to 20 down to 0-3 back and forth constantly until I start goin down hill or flat land. My EBP @ 75 mph was from 23-25, and vgt stayed around 40

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[justa03]

Your boost gauge would go from 20-0 psi? Odd if its dumping boost like that out of nowhere. All boost is controlled via VGT and the EGR valve. If the valve was stuck open you would see this but you said you deleted the EGR so the only other thing would be the VGT solenoid, maybe if you have a shorted wire or something causing the solenoid to suddenly change, maybe pinched a wire or something when doing the delete?

[justa03]

Check your FICM voltages and fuel pressure too under load just for a precaution.