FLF150LB

I have a 2005 f150 xlt 4x4 5.4 triton 132k miles. okay so the other day it started to misfire on cyl #3 so i made sure the plug was tight and replaced the COP. but now at idle (when in gear) it has an idle of about 500rpm and is shaking the cab(like can feel it bad) but once you give it a little gas and make the rpm stay at 800rpms ish it runs fine. What would cause this? The people at ford told me they will have to ddo a tear down to see whats wrong. But I would like to hear yalls input first.
If you need to know anything else just let me know

Thanks in advance! =D
FLF150LB

techrep

iTrader: (1)

when was the last tune-up ? plugs and COPs

FLF150LB

it was about 20k ish ago so not to long

techrep

iTrader: (1)

you did both plugs and COP's ... what brand ??

FLF150LB

They were oem i had ford do the work

FLF150LB

While heading to work today I decided to gun it to see if it would misfire...well it didnt it actually ran better then it has in a while. Though when i was at stoplights it would start to idle bad again (like 500rpms and dip to 350ish rpms occasionally). If i would give it some gas and hold the rpms up a little bit it dosent idle rough. I asked a few of my friends and one told me to make the computer needs to relearn the idle because it was compensating for the misfire for a while(undo the battery for 5min and reattach the battery and let it sit in park for 3 min, then in drive for 3 min, and then in neutral for 3 min, then back to park). and the other said i need to check my throttle body and see if it needs a clean (I havent cleaned it since i've owned it and i got it at 88k so I think it maybe time)
I was wondering if yall thought that maybe its a good idea to try this?

Thanks in advanced! =D
FLF150LB

techrep

iTrader: (1)

yes.. get some throttle body cleaner and MAF cleaner and clean both

FLF150LB

I cleaned the Throttle body and MAF the throttle body was Horrible. It helped out the idle and the shaking, but it still shakes some.

FLF150LB

This is what it looked like when i pulled it off, It was clean when i put it back on i forgot to take picture after it was clean it was getting ready to rain so

FLF150LB

We'll a code came up today and it's a misfire on cyl #3 so I guess it's time to check that again