A Challenge For The Veterans

windrunner408 · Dec 14, 2011

Ok well I dont really care who can help me with this but am just hoping someone can. I am hoping the veteran diesel techs have seen or heard of something like this to point me in the right direction for correcting. I have had a problem for a while that I can not for the life of me (or anyone else it seems so far) figure out what is going on.

The PROBLEM (Challenge) seems to manifest itself in the form of: I'll be cruising down the road say for 15 miles or so (say at 65-70 mph and with everything at normal operating temperatures) and then, like a switch, the truck seems to defuel and the boost level shoots up about 3-4psi and the truck feels like it has no power. WTF!!???

Now I can give you just about any parameter you would like to know. I have given these before on other forums but they seem to get me no where. I am hoping that through discussion of asking questions and trying different diagnosing techniques WE can figure out what could be causing this.

Any and all help would be GREATLY appreciated.

windrunner408 · Dec 14, 2011

Ok the only thing that I can correlate with this happening is Temperature and by that I mean Ambient/Intake Air Temperatures. The problem seemed to do this when OAT/IAT was 80*F or higher, then it worked its way down into the mid 70s, and now I noticed it with IAT at 66*F and OAT at 70-71*F.

windrunner408 · Dec 14, 2011

Is there such a thing as limp mode for the ECM?? Because that is what it feels like my truck slips into. What could cause this??

hawgdoctor · Dec 14, 2011

Thinking maybe the ebp sensor, or tube is clogged? What year is the truck, mods, etc....
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kevin · Dec 14, 2011

It loses power and the boost goes up, did I read that right?

SIX_OHH · Dec 14, 2011

Wonder if the solenoid is effed?

windrunner408 · Dec 14, 2011

hawgdoctor said:
Thinking maybe the ebp sensor, or tube is clogged? What year is the truck, mods, etc....
Sent from my DROIDX using Tapatalk

I have removed and cleaned the EBP sensor and tube. I read about guys with what seemed like similar problems with this being the cause but after I cleaned it, I still had the same problem. The truck is a 2006, mods are in my signature but ones that matter are EGR delete, Oil Cooler delete, Exhaust, SCT Tuner with custom tunes, ITP RR Kit, Spearco Intercooler, CCV mod, head studs.

kevin said:
It loses power and the boost goes up, did I read that right?

Well it requires more boost to run at the same speed I was cruising at on flat ground. Like a switch while cruising, the boost jumps up 3-5 psi. So I would presume that means less power is actually being produced.

SIX_OHH said:
Wonder if the solenoid is effed?

IDK, would a solenoid that is F'd do that??

kevin · Dec 14, 2011

So it feels like the motors being put under a load? Is your a/c on when its doing this?

windrunner408 · Dec 14, 2011

Yes it does kind of feel like the truck is towing something. Yes the A/C was on but it still did it regardless whether the A/C was on or off, because I thought it might have been the A/C as well but there was no change when I turned it off.

kevin · Dec 14, 2011

Well my truck was kinda surging like that 2 weeks ago , then it finally locked up for good on the side of the road.. I think some solinoids stuck in the transmission.. but I was having shift flares before that to.. hope thats not your case..

windrunner408 · Dec 14, 2011

I yea, I dont think that is my case. I havent noticed a change in rpms when this occurs and my transmission shifting seems spot on with my tune.

Nevertheless, what do you mean by "locked up"?? Did the motor or transmission or both lock up on you?? Sorry to hear about that.

windrunner408 · Dec 14, 2011

SIX_OHH said:
Wonder if the solenoid is effed?

Also, if the VGT solenoid was F'd, wouldnt it do this at other temps as well??

kevin · Dec 14, 2011

windrunner408 said:
I yea, I dont think that is my case. I havent noticed a change in rpms when this occurs and my transmission shifting seems spot on with my tune.

Nevertheless, what do you mean by "locked up"?? Did the motor or transmission or both lock up on you?? Sorry to hear about that.

Rpms never changed, It would just all the sudden feel like i was pulling a trailer for a.few seconds then go back to normal, Did that for a few weeks.. tranny locked up, it would move but it felt like I was doing a sled pull with nothing behind me:doh:

Pizza pig · Dec 14, 2011

check your line pressure in the transmission.

Hook up a 500PSI gauge on the test port on the side of the trans

windrunner408 · Dec 15, 2011

kevin said:
Rpms never changed, It would just all the sudden feel like i was pulling a trailer for a.few seconds then go back to normal, Did that for a few weeks.. tranny locked up, it would move but it felt like I was doing a sled pull with nothing behind me:doh:

pizza pig said:
check your line pressure in the transmission.

Hook up a 500PSI gauge on the test port on the side of the trans

While I don't want to discount any possibility of what my problem could be, I have to say that after this further discussion; I dont think this problem is in my tranny. I say that because when this issue occurs, it doesnt really feel like my truck has a load hooked up to it. The truck still feels as light as usually does when empty but simply requires more boost for a given rate of speed.

Now out of curiousity, if this was the transmission would there be any tranmission codes that would be thrown?? (may not cause any light but the code could be soft or something)

SSpeeDEMONSS · Dec 15, 2011

windrunner408 said:
Also, if the VGT solenoid was F'd, wouldnt it do this at other temps as well??

So it is doing it any temp above 66* IAT or 70* OAT?

Garrett

Probably getting paid at work to post this from my D1

Rob D · Dec 15, 2011

does it happen when programmed to stock?

windrunner408 · Dec 15, 2011

SSpeeDEMONSS said:
So it is doing it any temp above 66* IAT or 70* OAT?

Garrett

Probably getting paid at work to post this from my D1

Yes, this is what I am observing happen. It may do it at temps as low as 60*F for IAT or OAT. I havent been able to narrow it down to a specific number yet. I thought it was 80*F but it now seems to be lowering.

I just know for sure that it doesnt appear to do this when it is cooler out such as in the mornings when OAT/IATs are less than 50*F. This of course may change but so far I havent been able to recreate the problem when the temp outside is in this neighborhood.