Engine Surging / Ittaratic idle / Studderring
My 2002 F250 7.3 is having some probs. when I start the truck, the engine surges from 1500 RPMs to about 500. If I push on the gas and keep RPMs constant for about 10 seconds, when I let go it will steady the RPMs but when I drive it is rough and studders and hard shifts till the engine gets to operating temps. I just changed out the glow plug relay and that improved the studderring but now I have the surging issue. Truck has 270,000 on it and I just got it so not too sure what all has been done.