When im driving down the road between 40 and 70 about once a week my truck will surge really bad kinda like I mashed the throttle but it does it faster than I could ever get it to do just by mashing the throttle. The best way I can describe it is it feels like someone hits me going about 5 mph faster than I am. When it does this the motor revs itself for about 1 sec and then nothing and it never does it multiple times at most 2 or 3 times a week. I was wondering if someone has had the same problem or maybe if someone knows if this is a sign of something failing in the future? Thank you for your time and input.

 

Try the code search trick with the key. Do a search on here for the apps reset and try that mabey. Does the converter unlock and the tach go up but speed stays the same?

 

Could be the APPS.

Might try this: https://www.dieseltruckresource.com/...n&onlynewfaq=1

The codes will likely tell you whats up though.

 

No it actually gains a few miles an hour I think, I mean the truck surges forward when it happens so im pretty sure the converter stays locked but it happens so fast I have never been able to watch the speedometer.

 

Thanks for the input i'll try the apps when it stops snowing

 

My truck would do the same thing just before the VP44 died. I don't know if that is an indication or just coincidence. I don't think I gained any MPH, but you could hear my engine surging. Check your codes!

 

These are the two codes that come up
P0121
P1693

 

1693 is a "companion" code, usually means there is another code lurking in there. (need scanner).

P0121 is (i think) to do with the TPS circuit, or APPS since we don't have a throttle.

 

I got those codes with my hypertech ( will the hypertech show all codes existing or no?) I'll take it to a shop tomorrow and get them to throw a scanner on it.