Ignition coil.
An induction coil, used with a distributor for timing, to transform a vehicles battery voltage to a much higher voltage needed to create proper spark for all spark plugs of an engine. Calif. Exc.Calif. To 10/1990.

Ignition Coil

Fits Cabriolet, Corrado, Fox, Golf, GTI, Jetta, Jetta GLI, Quantum, Scirocco, Vanagon

1.8 liter. 4 cylinder, Federal. All Models; w/o 16 Valve. Cabriolet. California. Corrado; 1.8L. Federal, from 24E155001. From 15E027001. Vanagon; All. W/o turbo.
Ignition Coil - Repair or Replace
A failed ignition coil in your 1985 Volkswagen Jetta GLI can lead to anything from an intermittent misfire to a car that won't start.