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[amba]

Sure I remember reading somewhere it was possible to test plug leads and dispack whilst they are still fitted using a multimeter and reading the resistance between sets of leads.

Can anybody offer any further advise as would like to try and find if fault lies with dispacl or a lead before pulling the entire system apart to cure misfire I seem to have contracted

[cem_devecioglu]

this one ?
http://www.youtube.com/watch?v=c1zhgsnyZWw

[amba]

Thanks Cem...thats what I was looking for . ....assume those readings would be pretty similar on Omega V6 then ?

[Marks DTM Calib]

Not viewsed the video but yes, you can do a continuity test between plug lead ends (I would expect readings of 5K to 15K) of opposing cylinders e.g.

1-4
2-5
3-6

However, given the usual failure is often a coil pack corrosion one, this will NOT show up using a resistance test.

This is because the coil works by storing energy in the iron core, this is done by passing a current through the primary winding which creates a magnetic flux in the iron (you effectively store magnetic energy in the iron). When the current is removed, the energy has to go somewhere and as the primary is now open circuit, it is dissipated via the secondary winding which has more turns thus producing 40KV across the spark plugs

So when the iron in the coil corrodes, its not possible to store as much energy and hence the spark energy is much reduced....yet the coil resistance will remain the same.

If you could measure inductance you might well be able to detect coil pack failure.

[amba]

Is it therefore possible to test to establish if the dispack is faulty without removal ,as I really don,t want to remove the scuttle panel again as I have now got it fully sealed .

Pack was replaced with genuine Bosch not that long ago although accept even new can fail early.

Plug leads can be checked for Ohm resistance

[tigers_gonads]

Not viewsed the video but yes, you can do a continuity test between plug lead ends (I would expect readings of 5K to 15K) of opposing cylinders e.g.

1-4
2-5
3-6

However, given the usual failure is often a coil pack corrosion one, this will NOT show up using a resistance test.

This is because the coil works by storing energy in the iron core, this is done by passing a current through the primary winding which creates a magnetic flux in the iron (you effectively store magnetic energy in the iron). When the current is removed, the energy has to go somewhere and as the primary is now open circuit, it is dissipated via the secondary winding which has more turns thus producing 40KV across the spark plugs

So when the iron in the coil corrodes, its not possible to store as much energy and hence the spark energy is much reduced....yet the coil resistance will remain the same.

If you could measure inductance you might well be able to detect coil pack failure.

Perfectly put sir