4.6 engine. On a standard acceleration between 40 to 55 MPH the engines miss fires for some unknown reason. I have no engine check light and the spark plugs and spark wires have been replaced. Any ideas?

 

When the plugs were changed were they gapped to spec? Are the wires properly seated on the coils and the plugs? How many miles are on the fuel filter? Are you sure it is a miss and not a tranny shudder?

Regards

Jean Marc Chartier

 

40-55 mph sounds an awful lot like tranny shutter. Around that speed, the "insecure-ness" of the tranny could feel very much like a miss.

I agree with all that JMC has suggested, but I would definately consider the tranny shutter.