P0304 after restarting

I am a big fan of this forum, I have fixed many a problem with the advice of this forum. I have done the EGR port cleaning, which seemed to get rid this code at first, but now it comes back only after I stop some where for a couple of minutes and then restart. The engine runs perfect until I restart after a short shutdown, and I can tell immediatly that its going to pop up, because the engine will run rough. Any suggestions?

Its a 96 3.8 V6 Windstar.

P0304 is a misfire on cylinder #4, which is on the front, passenger side of the engine.

Clogged EGR ports is a leading cause of this.

You can try moving the spark plug to another cylinder, and see if the problem goes away, or moves to another cylinder.

Crud in / on the fuel injector can also cause this problem.....On as in a buildup of crud inside the "cap" over the spray end of the injector.
I have cleaned my injectors by removing them, and spraying a cleaner into the cap, flushing the crud out.

A spark plug wire can also cause this.
Also, the coil pack could be arcing on the cylinder #4 output.....through the epoxy case.....they have been known to develop a small crack in the epoxy, which leads to the arcing.

Also, this is a possible leak point for the lower intake manifold gasket.
Coolant can leak into the cylinder, causing the misfire until it is flushed through.
If you do those, buy the replacement gaskets from FORD.