Truck cranks and runs, When Idling, engine surges. Gets worse when you drive it down the road. Will surge & buck after 40mph. Replaced throttle position switch, coolant sensor, distributor, cap, rotor, plugs & wires. Removed upper intake, cleaned it out. New gaskets, cleaned throttle body including EGR ports, replaced MAP sensor, and replaced fuel filter. Seemed to help for about 15 minutes, then began surging & bucking again. Any suggestions as what to try next?
Friday, January 6th, 2012 AT 8:36 PM