Volkswagen Golf III (1992 - 1997) - 94 1.8 Ignition Coil Tolerances

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Thu 2 Jul 2009 19:36
94 1.8 Ignition Coil Tolerances - Javalin
Hello all,

Enjoying the heat? Phew.

Checking the resistance of the ignition coil on the above car (ABS) and the 1998 2l 8v gti (AGG) engines. Bentley has the primary coil at 0.4 to 0.8 ohms but the ABS engine coil is 3.9k ohms and the AGG has 1.9k ohms. Both secondary coil's are in tolerance.

Are these far enough out to cause misfire/weak spark? Worth replacing the ABS one (3.8k) ?

Cheers,

james

Edited by Pugugly on 03/07/2009 at 18:25

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Thu 2 Jul 2009 19:58
94 1.8 Ignition Coil Tolerance's - Peter D
The 0.4 to 0.8 ohms is the primary but you appear to be quoting the secondary resistance. If it was that high the car would not start at all. Regards Peter
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Thu 2 Jul 2009 20:34
94 1.8 Ignition Coil Tolerance's - Javalin
Ah - sorry - I meant 1.9 ohms and 3.8 ohms - the secondary is about 3.5k or so for both.

James
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Fri 3 Jul 2009 09:08
94 1.8 Ignition Coil Tolerance's - Peter D
Does your meter say zero when the leads are shorted together. Regards Peter

Edited by Peter D on 03/07/2009 at 09:08

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Fri 3 Jul 2009 10:15
94 1.8 Ignition Coil Tolerance's - Javalin
Hi Peter - Yes it does. (digital multimeter)
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Fri 3 Jul 2009 10:27
94 1.8 Ignition Coil Tolerance's - Peter D
Explain the misfire. Is it OK when cold but starts to misfire when warm/hot, A random chuff/miss not related to one cylinder. Regards Peter
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Fri 3 Jul 2009 10:37
94 1.8 Ignition Coil Tolerance's - Javalin
Hiya Peter,

It seems to run ok for a second or two then you hear the rev's drop and then it picks up again. If you put a timing light on it - you get moments when the light doesn't trigger - I guess because the spark is not enough to trigger the light? I've checked with a inductive pickup on a picoscope - good spark and burn time from the king lead, but not so good on the 4 plugs - but im not sure if thats just how-the-pickup-works as its similar on the other cars we have. Its had a new plugs, leads, dizzy arm & cap.

Seems slightly better when cold I guess.

James
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