I have a 1992 F150 with the 5.8. It runs good when cold, idling and wide open throttle. It surges or misses when warm and at a constant speed. You can feel a slight miss or hesitation when at cruising speed. The truck is new to me but so far, these are the the things I have done or replaced.
New plugs, wires, cap, rotors. New IAC, cleaned EGR and new TPS. Cleaned throttle body, replaced air and crankcase filters, new pcv valve. I have checked timing, checked vacuum hoses and tried to find any intake air leaks but have not found any.
I haven't checked fuel pressure or tested anything with a vacuum gauge as I do not own any. Yet.
Please help! What might be causing this irritating problem?
have the same problem?
Thursday, April 19th, 2007 AT 1:10 PM