I have a 2005F-150 that stutters when doing about 40 mph and on a incline. I thought it was a dirty fuel filter 3 years old, I replaced the fuel filter but the SCREW still stutters when I'm on an incline, giving it gas and on an incline.

Been doing this for about 4 months. Happens every time when I'm on an incline. It's smooth on decline or flat road.

Any ideas?

 

How many miles on the sparkplugs? Sounds like a low grade misfire.

 

Yep, sparkplugs.

 

Yeh when mine would do that it would do it around 45 mph all the time, turned out to be the COP. It wouldn't throw a code and it probably won't, but it's more than likely that.

 

The spark plugs have about 30k on them.

 

What brand plugs, and how many miles on the cops?

Fuel-related - you may want to check the backside of the FPDM for corrosion.

 

Thanks. I will check the FPDM...this has been driving me nuts.

 

You want to follow the above first. If that doesn't get it, you may be having an issue with the shift module, it's a common defect in this YM truck. The issue is the transmission is shifting in and out of OD rapidly. Tranny life will be short if not fixed. There was also a tranny reflash to correct lousy mapping for the shift module. You may still have a unit with the old programming. Might call the dealer with the VIN to see if yours has been reflashed. Until you find the issue, I'd strongly suggest driving the truck with the OD locked out until speeds exceed 50 mph.

 

^^^

 

If the plugs don't work this is your answer.
http://www.livernoismotorsports.com/...epair-Kit.html