Help !!!!
When cresting a hill, and heading down the rpm decreases and increases without throttle position changing. Change is quite harsh. Does the same in cruise.
It also does the same when third selected with auto tranny. Only seems to occur above 60 to 70 kilometer per hour

Is it stock or has the chip been replaced? If it has an aftermarket chip put the stock one back in and recheck.

The chip is a stock chip

Thanks for your imput. Found the problem to be the injector pump causing the surge.