I have made several posts regarding my 95 B4. I have replaced several parts and dumped countless hours chasing this problem only to be left frustrated and the car running no better.
The car runs great and after 20-30 minutes, "boom" it starts to mis, only on 3 & 4. There is no spark jumping from the coil from those 2 points and only those 2. When the car is running, it will run and cycle the fans...heat up and cool down but, in 20-30 minutes it is all done and wants to misfire.
What been done to remedy:
1. starter and battery (after several no start attempts)
2. CS (Blue coolant sensor)
3. all relays (every single one)
4. ECU and relay
5. spark plugs
6. fuel pump and filter and relay
7. opened exhaust
8. new coil, less than 5k ago
cyls 3 and 4 are on the same coil in the coilpack, sounds to me like another faulty coilpack. i dont care if its only 5k miles old, ive seen brand new electrical items fail right out of the box. the fact that the problem occurs after a period of time (when the coil gets hot) only supports the coilpack theory. try to get it warrantied, score a good used one to swap and test or worst case bite the bullet and order another. gl
Took the advice and hit the local yard. Scored the Ford coil and a set a new wires for $30 bucks. Bought a set of MSD wires and dumped about 3 hrs into the conversion. Final verdict, Effing Kick Ass! Nice upgrade and it solved the problem I have been having. Never thought a coil with 5k would go bad....
check the main ground on the "cannon" plug, and look at the ground wire going to the coil pack.... is it burnt or fried?
I had this issue with my mk3 and it was frying the the ground wire for some reason. replaced the engine side engine harness and it started to happen again. it fried the ICM on the coilpack. I ended up cutting the ground wire from the cannon plug and to the coilpack, ran an inline fuse off the ground on the coilpack and grounded it on the back of the head. the ground wire from the cannon plug I elongated and grounded to the chassis with the other grounds by the battery.