Not even sure what to check for.2004 4.6 140,000 miles. No check engine light and no codes stored. Engine starts up great,idles good,maybe a little rough but not bad. When you step on the gas,even floor it,the rpm's jump to 1200 for a second then back to idle speed even though my foot still has the pedal on the floor. Keeps doing this as long as the pedal is pushed down. Of course it is totally undriveable like this. Any help would be great!!

 

Does your 2004 have the electronic throttle body or the cable actuated throttle body?

-Rod

 

it is drive by wire

 

I thought there is a procedure to calibrate the throttle body after replacement and was going to suggest you go through those steps. But, after checking the factory service manual, I don't find any such procedure mentioned.

-Rod