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?
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?
Apr 19, 2007 at 1:10 PM