1993 audi 80 2lt petrol - no start

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Sun 26 Jun 2011 16:51
1993 audi 80 2lt petrol - no start - macman

my audi 80 avant 2lt petrol won't start, it has spark at the coil but not at the plugs. I think it may be the hall sensor.

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Sun 26 Jun 2011 17:13
1993 audi 80 2lt petrol - no start - unthrottled

Very plausible. What do you mean by spark at the coils? Coils can suffer voltage breakdown leading to no spark and appear fine on a multimeter.

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Sun 26 Jun 2011 18:13
1993 audi 80 2lt petrol - no start - macman

If I earth the coil lead, it produces a spark, there is 12 volts at the coil, but disconnect the 2 wires and connect then to a volt meter I only get 5 volts when cranking

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Sun 26 Jun 2011 18:57
1993 audi 80 2lt petrol - no start - RT

5 volts may be correct - in those days many cars had "dual" voltage for the coil - under normal driving it was 5-6 volts by using a ballast resistor but given the full 12volts when the starter motor was running - as the coil is a contant voltage multiplier it gave double the voltage at the plugsv during starting.

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Sun 26 Jun 2011 20:26
1993 audi 80 2lt petrol - no start - macman

the voltage is increased by the pulsations from the hall sensor, so surely if that is not 100% spark to the plug leads would be nil. As the coil gives a spark I still feel the sensor is at fault

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