My 1999 F150 XLT has developed a miss or skip when the engine is under a strain. When I am going up a hill or when I accelerate at a rapid pace the engine seems to be missing. Once I have topped the hill or have reached the desired speed (like going from 50 to 70 mph), the engine smoothes out.

Thinking it might be plugs or plug wires, I took it to Advance Auto Parts. The tech tested for codes using one of the hand-held testers, but nothing showed up. He suggested it might be the fuel filter. Does anyone know what my problem could be? Is it something I could easily fix? I have had the truck about a year. It has 120K miles on it. I have no idea if the plugs and plug wires have ever been changed. If the problem is the fuel filter, is that an easy replacement?

Any help you can offer will be appreciated. Thanks!

 

Check your spark plugs.

 

Anytime you buy a vehicle and don't know the history, assume it has never been done. That's what I do anyway. So sounds like a nice tune up may be in store for you. Fuel filter is about a 15 minute job, relieve the fuel pressure or let it sit over night, get the fuel line removal tool, pull and replace. Plugs and wires are not a bad idea. I'm assuming since you said wires, that you have coil packs? Instead of coil over plugs. 4.6L? Make sure and go with the recommended torque specs on the plugs, which is 28ft/lbs with no antisieze if your using motorcraft replacements (recommended) See what happens after that. If the misfire is still there, Look into the coil pack/packs and cleaning the MAF sensor. Check your coolant for color, smell and level. Change the oil. I dunno, you know... the basics.

 

#1 check the codes
#2 prepare for a plug change

 

lol wat