Engine skip when accelerate from 0-40mph ,The air throttle valve (New)..press on accelerator (skip) and let up press again (skip) uip to 40 mph after that every thing ok HELP

 

Hi Bill,
Welcome to the site.
It would help a lot if you could provide some addl info like year, model, engine, since there are many differences from model to model, year to year etc.
What kind of maintenance has been done? When and so on. This is important since if the spark plugs haven't been replaced for many miles for example, it's a lot easier to make an intelligent suggestion knowing some past history.

 

Ford F150 5.4 Lariat 2005 78,000 miles it happens at the times not always

 

You're in the mileage park for coil on plug problems. You could very possibly have one of the coils, coil boot or spring at the bottom of a coil problem. Many times this type of misfire will not set a code in the computer, but with the right kind of scan tool with mode $06 capability could direct you to the problem cylinder. You could always do as we say, "Let it develop". Then when it becomes consistent it would be easier to find.
Don't want to frighten you , but a bad coil can take the PCM out and that is more expensive than replacing coils.

 

We are experiencing the same issue and was wondering if these could have anything to do with the recall on the Fuel Injectors. I have 2005 Ford F150 and just replaced the coils, plugs, pcm, fuel control module and now they are telling me I need a new engine because the PCM held the Fuel injectors open which I believe caused the cylinders scoring. We have 100000 milese on this truck.