Having a problem with my girl friends 99 passat with a 1.8L turbo gas engine with a 5spd. engine is missing on only one cylinder. I have replaced the valve cover gasket that was leaking oil, replaced the spark plugs and the coil. coils are all good and there is good power and ground going to the coil. i have also replaced the plug connector. this cylinder will not produce a spark! I put that coil on another cylinder and it produces spark. I have tried everything. Even the voltage to all the coils are the same. I have ben a auto tech for many years. she is driving my 95 monte carlo with a 3.1 and wants her car back cause of the fuel millage. I am using one of our loaner cars from work. I AM STUMPED. PLEASE CAN SOMEONE HELP?

 

there is a small controller on top of the air filter box with 2 plugs on it. one on each end. its abought 3 inches long and bolts down to a oval heat tab
it controlls the spark
cost around 100$

they switched to a diffrent system on the newwer ones
are your coils the bolt down style? if they are then you do have the controller on the air filter