ok so my problem is that when im driving down the road the truck will surge and my tach will jump a few hundred rpm. i notice it more when the cruise is set. i think it may be either the throttle position sensor or my cruise control servo. any ideas?

 

I'd start with the TPS... noisey ones will caust the TC to lock & unlock causing a surging feeling

 

Mine does the exact same, let me know what you find for the fix

 

your's is for sure going to be the TPS... 99% of the time that is what it is. there is 1 other possible failure which is a wire inside the tranny. since tps's are cheep and quick to swap, start there.

 

even though it only does it when i use cruise?

 

You most likely have a loose vacuum line running off of your throttle body which controls your cruise control speed.

 

one of the guys i work with said it could also be the egr vavle. he said it was probly the tps though so as soon as i get the time im gonna check it

 

02 kid.. you dont have an egr valve... er, wait a minute, which motor do you have? not sure about the 4.7's but the egr's went byebye in '97 on the 3.9/5.x motors.


4x4Kota... check real closely w/o the cruise on to see if it surges. if you have a tach, you should see a 200 rpm change in the rpms. I havent heard of the vacuum line causing any problems on the cruise, but that doesnt mean it cant happen. I'd think with a vacuum leak you'd have real funky cruise operation...