Anyone have an idea why this is happening??

Was cruising along today pulling a hill and noticed I was just flying by everyone else.

Had that "Man I love my truck moment" when I realized I was 35kmh over the limit

Fiddled with it the rest of the way home but kept doing it.

Soon as I hit "set" she just keeps climbing up the speedo.

 

If you have a potentiometer check that it hasn't gotten bumped. Mine will do that if the potentiometer is turned up too high.

 

Sounds like a vacuum problem to me, have you checked all your hoses? Sometimes turning up the pump causes that too but I can't remember why right now

 

mine does this after I got new switches. as soon as I press on and set it goes to full throttle. I adjusted my Potentiometer many times and it didn't change. I've heard it could be the servo but never have checked it or got a new one yet to be sure. It may be your problem though.

 

Mine does the same thing. Someone told me to put a restricter of some kind in the vacuum line

 

Ain't that a feature?

 

Yep, it's an undocumented feature.

ARM
Automatic Race Mode

Seriously, I suspect the PCM is expecting the TPS to swing (throttle movement), and if it's fixed, ie a potentiometer, it overcompensates a bit. On a stock motor it's not really an issue, but if you have things turned up so throttle response is snappy, it could get goofy.

With a little vacuum flow restriction taming down the throttle response when in cruise, it should settle down to reasonably normal.

 

Isn't this the 3rd time you've been bang on and helped me out??!!

I so need to buy you a box of beer and say thanks!!

It was the POT.

 

I am glad I could help.