Coil and ignition leads question
08-18-2010, 07:06 PM
#1
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Coil and ignition leads question
My '91 GT has almost 20 years of operation (77000 mi) on original coils. Also found that rotor caps and ignition leads are barely acceptable. Could this explain the somewhat erratic idle I get sometimes and the reluctance to fire up from first attempt when fully warm?
08-18-2010, 07:31 PM
#4
Drifting
On the 32 valve engines, erratic idle is usually a bad idle stabilizer valve.
You can check the ignition wiring at night to see if there is any arcing. The ignition wires should be replaced as a set if they are hard and brittle.
The rotors can be measured for resistance. It's listed as 1K ohm suppressor resistance for S4/GT/GTS.
You can check the ignition wiring at night to see if there is any arcing. The ignition wires should be replaced as a set if they are hard and brittle.
The rotors can be measured for resistance. It's listed as 1K ohm suppressor resistance for S4/GT/GTS.
08-20-2010, 08:35 AM
#6
Porsche uses a copper wire high tension lead with minimal resistance. The resistance is applied via the plugs on the end of the high tension leads, so that each HT lead has similar resistance values.
I would replace the two HT leads from the coils to the distributor caps with copper wire leads using the existing plug connectors. Old VWs used the copper wire HT leads, so you should be able to purchase some copper wire HT leads and make your own.
+1 to dark garage check for arcing and if you turn the a/c off and the electric fans are not operating you can sometimes hear the "crack" of any arcing from the HT leads in other areas that my be arcing to earth that you initially cannot see.
Tails 1990 928S4 Auto
Tails 1990 928S4 Auto
I would replace the two HT leads from the coils to the distributor caps with copper wire leads using the existing plug connectors. Old VWs used the copper wire HT leads, so you should be able to purchase some copper wire HT leads and make your own.
+1 to dark garage check for arcing and if you turn the a/c off and the electric fans are not operating you can sometimes hear the "crack" of any arcing from the HT leads in other areas that my be arcing to earth that you initially cannot see.
Tails 1990 928S4 Auto
Tails 1990 928S4 Auto
