i recently purchased a f150 fx4 5.4L w/ 18" rims and lt275/65rx18 owl all-terain wheels. at about 1000 miles i have noticed that when i start my acceleration, there seems to be a slight delay or hesitation. i can't seem to determine if it is coming from the engine or the rear or the tires. any thoughts?

 

I think this post is in the wrong section. The'll move this later on.

Anyway, what year is this vehicle? carburetor? tbi (Throttle body injector)? fi (fuel injector)?

I've encountered this problem before and here's what my recomendation.

Three things I want you to check.

1. Take out your IAC (Idle Air Control solenoid) which is located on the throttle body. Clean it with a throttle body cleaner and a brush. Clean the spot where the IAC goes in to the throttle body.
If that does not work you may have to replace the IAC $29.

2. The TPS (Throttle Position Sensor) also causes problem which is located below the IAC. The TPS at IDLE provides voltage value to the computer and that's what how computer determine the position of the throttle plate. If there is a dead spot on the TPS providing incorrect voltage then it will throw the computer a little bit. The TPS can't be cleaned and you just have to replace it $19.

3. The MAF (Mass Air Flow sensor usually located right after the air filter box) or ACT (Air Charge Temperature sensor usually located on the side of the air filter box). Try cleaning them with some throttle body cleaner and let it dry.

Check the connectors as well of all sensors.

 

I assume it's an 04. The 04's are "drive by wire". There is no throttle cable, There is a sensor at the pedal that tells a motor at the throttle body how much gas you are giving it by the position of the pedal. Some people have noticed a hesitation when first stepping on the gas, some worse than others. I have an 04 but I don't notice any hesitation. Do a search for "hesitation" or "throttle" on the 04 F150 forum, this subject has been exhaustively discussed there.

 

Moved to 04 forum

 

Brooknbrown, take it to your dealer and have the throttle reprogramed, there are other posts about this and a simple updated reprogramming fixed this problem in each case.