1994 E350 cutaway bus skip.

I have a 5L gas engine. I have tuned it with new plugs, wires, distributor cap and rotor, checked and or replaced vacuum hoses. New fuel pump and fuel filters. New alternator and batteries cleaned, cleaned battery terminals on both batteries.
The vehicle starts very easily and the idle drops back after warm up. The problem is an intermittent stop (skip) as though the engine looses ingition for just half a second. There is no pattern here the stop. There also not backfire during the stop.

The vehicle accellerates very well and has lots of power. Out on the road this intermittant skip is still there.

Any suggestions would be appreciated. Check engine light goes out on start as normal.

thanks
bigbaribob

Check distributor pick up and ignition module.

Check distributor pick up and ignition module.

Is there a funcion test for the ignition module without having to have an $80 diagnositc test run by the dealer?
Thanks
Bigbaribob