Striaght to the point

2001 Ford F150 4.2L
4 spd auto
63,000 miles

A hestitation has developed when under load. Almost like a miss, thought not that obvious. I am going to change the plugs and wires this weekend but wanted to know if anyone else had any ideas. I cleaned the injectors last weekend with no help.

Thanks

 

Change the fuel filter and clean the throttle body. If that dont do it,clean the MAF sensor and the IAC valve.Or,just do all the above. :santa:

 

MAF Sensor was going to be next on my list if plugs and wires did not do it. Thanks for the input. The main reason I came on the board about something failry straight forward was because I had heard that some people have problems with the coil pack going bad. I didn't know if this was a symptom of that or not.

 

I have been seeing posts pop up about the coil pack going bad on later model (2000-2003) 4.2V6s.Kind of ironic that in 2000 they changed the coil pack design from prior years.

 

Had a miss under load I could not locate for a long time. I have a 98 with the 4.2 engine. I changed all four 02 sensors as the truck has 70 k on it. It didn't make a difference. I changed the plugs and the wires, and it went away. The platinum plugs were only 35k old. Inspecting the old ones, I found two that were 15 thousands gap over what I installed them at, I believe that this was the cause and has had no problems since. With new plugs, Motorcraft platinum, as per original equipment specs, and Bosch wires (this time) the truck drives like new with no skip under load, the truck is a five speed standard.

 

What is test procedure for the coil pack? I know you can test the ohm's across two lugs to test to see if it is bad but I can't find it in the manual right this second. Or maybe I have been inhaling to many exhaust fumes....

 

I've noticed a similar hesitation in my truck the last 2 days.

While I'm always looking to spend money keeping it running right , I'm not so sure it isn't due to the fact I filled up at a different station the other night.

I'm going to fill up at my usual place in a day or two to see if the problem goes away.

It sounds like my hesitation is less noticeable than yours - I get it on the highway when accelerating from 70 to 75 mph in OD (light load). If the trans kicks down, there's no problem.

If it doesn't go away, its new wires and plugs for me! BTW, plugs are only 20K old - so I'd be disappointed if that's my problem.