F15006

I have an 06' F-150 with over 163000. Just recently, it starts to shimmy when trying to accelerate gradually with the A/C on. It doesn't occur as often when the A/C is not on. Any thoughts or suggestions?

techrep

iTrader: (1)

F15006

Last tune up-last year. Motor-8cyl. 5.4 L V8

eff1fifty

redfishtd

Does it do it going up a hill without ac . Cel will not show up until it reaches threshold setting which is quite high . Not a good idea to push it to set cel as its hard on cats . You can see misfires on mode 6 or on torque pro with android phone /blue tooth reader under test results you get raw data by cylinder . Torque pro $5 ,blue tooth reader $20 amazon and an old android not even activated or laptop .
Replace all boots ,clean all cop terminals ,use very small amt of dielectric grease on boots . Sp 515 plugs prone to failure use sp546 . Clean carbon out of tip area of plug in cyl with carb cleaner . Torque all plugs 25 to 28 foot pounds .
You may need to change out injectors for new not remans . Check all connectors for lock on ,fix broken ones .

F15006

No, originally it would do it when running the air, but now it happens when accelerating, even without the air on.

F15006

Yeah, it does it while accelerating either up hill or on the street. Do you think a complete tune up would help?

redfishtd

These engines are very fussy about plugs . They must be done correctly as they sit 5 inches down in the head . The low voltage that is used to trigger cops and injectors is subject to corrosion . latest plugs are sp546 , factory cops rarely go bad they just get corroded connections . When using dielectric grease use it sparingly it is an insulator keep it off metal parts mostly . Boots on plugs go bad with heat and oil ,no mater how pretty they are change them . They hold back 30,000 volts from jumping to heads . If it still misses get torque pro and find cyl that is acting up . I have 192k and 7 of orig cops are still good . Probably should not have changed the one I thought was bad . Boots should be changed every plug change at 60k mi .
You can't trouble shoot this engine until ignition circuit is perfect it causes too many symptoms. Start there . Blow out all dirt first and keep everything clean . If these are orig plugs have lisle extraction tool first . Fix all connectors that don't lock on . Aluminum heads require care installing plugs by fingers. Clean threads and plug tip area out with carb cleaner to dissolve built up carbon , use rubber socket and great care installing plugs .
These years have bad injector series in them it is prudent to change them all with new after 125kmi . Leaking injectors can kill your motor. Good ones are not cheap .. I believe amazon has some that are not too expensive .
I wouldn't fool with remans .