cowboybarber

Story:

Today I was driving around everything fine and dandy. I stopped at a stop sign and all of the sudden the truck starts giving itself gas. I had to really hold the brakes to keep it from going into traffic. Then I put it into park and the truck keeps revving up to about 4000 rpms so I quickly shut it off. There were some cars behind me so I restarted, rode around for awhile seeing if this would happen again but it hasn't. Just wondering what you guys think it is.

I posted a few days ago that my rpms started acting funny going from 1000 back down to 500 on and off when at idle.

Any input?

05 super

my 97 150 used to do this when it got really cold out ( -40) i had an airaid intake on it and when all that cold air hit my throttle body it froze open. riddin the brakes wasn't fun. my 90 f250 had the k&n on it and same thing. maybe something to do with the iac. ( idle air control)

cowboybarber

Do the 2004+ have an IAC?

05 super

not sure. must have one in there somewhere.

94'snap

Did you make any changes to the intake?

cowboybarber

Nope sure haven't. The only thing mechanically I have done at all is replace the spark plugs. But I will say that after I changed the plugs, the idle started acting funny like going from 1000 and back down to 500, but I cant see what plugs would have to do with that. Out on the road everything acts normal.

cowboybarber

For the record I just found this on another forum:

A 2004+ 4.6 in a F-150 does not have an IAC. Throttle is all controlled by wires and computer and electronic throttle body.

05 super

could it be a throttle position sensor? any codes?

cowboybarber

No codes no light..yet I was thinking maybe tps also. I might change it out just to see.

06f150lariat

take it to the dealership, it sounds to me like its a problem with the computer...our trucks have a "fly by wire" which is an electronic accelerator (ie: does not use cables, thats why when you hit the gas it hesitates just a little bit, then kicks in, computer trying to work)