I am trying to help my dad with his truck, got ford coil, wires and plugs, says will only rev to 2300 rpm and misses like it is only firing on part of the cylinders. Being an old certified non Ford tech have ran thru a few thoughts with him and been doing some research and keep coming up wiht a vacuum leak or IMRC (I think) failure, has also new fuel filter, any thought would be great, Thanks

 

What are the codes?

 

Plugged cats?

 

Make sure the spark plug wires aren't crossed.

 

 

Fuel Pressure?