I've recently noticed that my truck has a slight surge in the idle. It will only seem to do it in drive, pop it into nuetral and it stops. Does not happen all the time, only notice when at operating temps. I do have J/A and Predator, but have not noticed/payed attention to which one does it more or at all. It's not enough to move the truck just hear it. Runs fine other wise. Any ideas?

Sorry if this has been covered, the search was not working.

I have a similar problem. Except mine surges enough to move the truck. (idle to about 1,000rpm) It happens at random times with no warning. Maybe twice in 2 weeks its happened.

Thats common with performance chips

it might be the fuel pressure return sensor