1995 Caravan

1995 Dadge Caravan with 3.0 V-6. While driving this mini van about 10 miles, it starts dying to the point I have to pull off the road and sit there about 10 minuets. Engine cranks but no start. Then the engine slowly starts runing on two or three cylinders and finaly picks up all cylinders. after this happens, it runs like it suppose to but the check engine light comes on. Flash code #43. Book I have says code 43 is
"Spark interface circut". I Gave it a complete tune up, replaced the fuel filter, air filter, changed oil & filter, replaced the coil & map sensor. The van ran great untill a few weeks ago and started doing this. I don't want to keep replacing parts, hoping to stumble on the right on. Any one know what could be the problem? thanks, Jim