ANYMORE TROUBLE SHOOTING IDEA'S. HAVE TRIED THESE. STARTED WITH CODE E34 CLEARED CODE RAN LIFT AGAIN RE-CKED EACH COIL PACK. CODE DIDN'T COME BACK. ANYTHING ELSE TO CK WHAT DO U THINK I AM MISSING DID SPARK TEST ALL CYL-S FIRING ONLY THING THAT WAS DONE SPARK PLUGS WERE CHANGED BY SOMEONE ELSE. FIRST THING I CKED WERE PLUGS EVEN SWAPPED THEM OUT 2 TIMES. CUSTOMER STATED THE ONLY THING WAS DONE WERE THE PLUGS CHANGED. LIFT RUNNING FINE UNTIL CUSTOMER CHANGED PLUGS.

First thing is to make sure none of the wires are broken in the coil connectors. Second is that you can start the engine and disconnect number 4,3, and 2 coil connectors and the engine will still run on number 1 cyl. Then connect number 2 and disconnect number 1 cyl. Keep moving along so you have the engine running on each cyl by itself. If the engine dies or runs rough on any cyl then that coil, spark plug, or cyl. is probably bad.