Hello guys hoping for some help or to get pointed in the right direction.The truck is as in signature with about 400,000 km on it.
The problem i am having is with the throttle. The truck acts like it wants to die off just for a second or so then all goes back to normal. I will have my foot in same position and rpms will drop by 1 to 2 hundred rpm and you can hear a difference in the turbo then it goes back to normal. The problem is more clear when the truck is cold. The truck besides this runs and starts fine hot or cold. It does not idle weird or if you stay on it hard it runs fine.

Things i have done:

Truck has never thrown a code
Truck has dtt noise filter
cleaned IAT and MAP sensor
multiple times tried doing apps reset
All battery connections are clean with dielectric grease on them
Problem is still there with cruise control on
runs the same with chip on or off
steady 12 to 16 psi to injection pump from fass(all filters are clean)
tried wrapping the on wire from alternator to pass battery with tin foil-no change
with truck off both batteries have 12.6 volts

I think thats all i've done off the top of my head.I just cant nail down the problems vp44? or apps?

thank-you

 

Maybe you need a new apps? My 03 does the same thing. Idles fine and good mpg still. I've tried resetting the apps too, with no change. I'm going to try a new apps someday.

 

My truck has started doing this but its very slight and I can't see a change in RPM onthe tach.

I figured bad fuel at first but have a few tanks since and a new filter and I have drained the wateer/fuel valve a few times but it still does this in the lower RPM range.

Could this be a bad injector?

 

thanks guys for the help, advice and just taking the time to read post. This morning I cleaned the main ground on the block from passenger battery(helped maybe?). I also had both batteries and the alternator tested everything is ok. Weirdly enough it was as noticible today for some reason?In my truck anyways i dont think its an injector cause it idles,runs and cleans up smoke as it always has.My egts are also the same as usual. My next step I think is going to be a timobo apps I think, unless anyone else has any other tips or ideas?

Thank you.

 

I have had that problem with my company truck (2004 w/auto) and my 2001 with 6 speed. I went through all of the cable connectors, clean and dielectric grease, reset APPS. everything good to go. Been fine for several months now.

If either one of my trucks start acting up again I am ordering a TIMBO APPS and see if that does the trick. The APPS is just a potentiometer, and they do wear out.

Let us know what you finally do to fix it. Good luck.

 

All I've read is good stuff about Timobo (spelling).