hello, i have a 2005 ford f150 4wd 4.6 ive owned the truck about 15 months and its always had a bad idle and has slowly been getting worse. a brake stand has never been possible and performance has been getting terrible. no CEL, the motor was pulled at 100k (now at 105k) everything was cleaned, heads replaced, all gaskets replaced, plugs, COPs, fuel filter, TB, air filter replaced, had zero effect towards the problem. ive been on every forum and have done everything everyone suggested and nothing has worked. i appreciate all the help i can get, im about 4k in to this. also have had this hooked up to a snap on SOLUS and it came back with no errors, misfires, or anything eles.

 

Fuel pump driver module under the spare tire??? "FPDM" if its older than 3-4 years replace it.
Dorman 590-001 Fuel Pump Driver Module, cost about $57.00 ebay.