as well as my astra 2.2 sri i have a bmw320 coupe 1993 e36 does have a running problem at mo. had car ecu read and no fault codes i think the plug insulators are breaking down which i can replace for £45 which is fine but could also be the coils. as its a 6 cylinder it has a coil on each plug does anyone no how to test the coils with a multi metre please. any info would be great thanks