brandon86

Hi i have a 1986 f150 5.0 302 with electronic fuel injection and ive been having problems with the idle it surges somtimes and it looks like the rpms are steady but the truck vibrates though the cab and i checked for a miss but its running on all cylinders and it seems like it does it when the trucks hot or theirs a hot day out. So with that said the whole ignition system was replaced at the ford dealer then the idle air control valve was replaced and the intake was taken off and the gasket replaced. Then the map sensor and the coolant temp sensor, new dist cap, rotor, sparkplugs, and wires. plus a new computer. the fuel system was gone over new filter and it has excellent pressure at the fuel rail. And i checked the vacuum and their are no leaks and it runs at about 15. now i had a new block put in this truck in the past and it had this problem ever since. and i had my original heads sent out and rebuilt the compression on the new motor is excellent. Me and the mechanic at ford dont believe its a mechanical issue. the only thing changed when the new motor was put in was the o2 sensor so im wondering if it could be that. The truck does smell rich when its idleing but ive put about 700 dollars worth of parts and sensors in this truck and im getting nowhere it drives down the road no problem it doesnt miss a beat. somedays ill start it it idles nice and smooth but when it warms up it starts to vibrate the cab so i wouls apreciate any help thanks Brandon.