Hi there, i have a 2005 F150 4.6L V8 XLT CrewCab,......idle is going up and down 500rpm to 800rpm, when you put your feet on the gas pedal, it stalls,...when you come to abrupt stop,it stalls,..when you reverse,it stalls,..but it runs perfectly in the highway,.....already replaced the TPS-Throttle Position Sensor, clean the MAF and replaced the air filter but still has the problem,...i've read to clean or replace the IAC valve,...but cant find it,....please help as we are living in an outskirts,....thanks

 

Clean the whole throttle body... And look under the truck by the spare tire. If you see a box with a wire going to it it's your FPMD.... These are known to rot right out and cause tons of drivability issues... If it looks heavily corroded then swap that out ASAP.

 

Like said clean the TB first and maybe change fuel filter and try some injector cleaner/dry gas in it before you spend anymore on it

 

hi guys,.....your advice works like a miracle,.....i cleaned all the things from air filter to maf up to throttle body with a carburator cleaner,......and after that,....it runs like a dream,....

thanks for the help....