No Spark

[Donno]

95 Disco Standard

Any thoughts on no spark from the coil?

Seemed to happen intermittently and now won't start at all and have traced it to no spark. I've done the 4 voltages at the coil and they seem good. For test 3, amplifier switching, I'm getting 12 volts with the ignition off where it says it should be zero. I seem to remember that this test was an error in Rave manual so not sure on that? Can anyone confirm proper procedure?

I have already fitted new coil and amplifier. New wires, cap and rotor. Pickup in the dizzy seems to have the correct resistance. I'm going to check the air gap and check the continuity of all the wires including the relocation wire for the amp. Anything else I can check?

Cheers

 

[Swedjen2]

Looks like a complete list.
So is it running?

 

[Donno]

Nope, I'm at a loss. Only thing that doesn't check out is the voltage between battery + and coil - with the key off. Getting ~12v and Rave says should be 0. Maybe try the old coil to see if the new one is maybe bad.

I'll look up checking primary and secondary resistances on the coils to check too I guess.

Thanks

 

[Donno]

Ended up being a bad rotor even though new. Put the old one back on out of desperation and she fired right up! Running great now! Serves me right for not going genuine parts.

Thanks

 

[Swedjen2]

I'm on a Land Rover email list and follow various problems people are having with RRC's, Disco's, etc. Cap and rotor quality is one of the constant themes. Get the red Powerspark rotors. AB sells them.

 

[discostew]

Make sure the distributor is pulsing a ground to the coil while cranking. When you put 12 volts on one side of the primary windings it's going to end up at both terminals. The one going to the distributor should get grounded 8 times in one revolution.

 

[llamasayswhat]

Rotors is the big smoking gun. We went through no less than 6 on a customers car(every aftermarket, genuine, lucas) and settled on one from distributor doctor out of the UK. They would work for a few weeks then just cut out and fail. They aren't insulated well enough, so eventually the spark is able to ground through the plastic in the rotor and not actually make its way out of the tip into the cap. Knock on wood, he hasnt been back for that issue yet.

 

[discostew]

Rotors is the big smoking gun. We went through no less than 6 on a customers car(every aftermarket, genuine, lucas) and settled on one from distributor doctor out of the UK. They would work for a few weeks then just cut out and fail. They aren't insulated well enough, so eventually the spark is able to ground through the plastic in the rotor and not actually make its way out of the tip into the cap. Knock on wood, he hasnt been back for that issue yet.

This is exactly right. Simple test is check for spark at the coil wire, if you have it, put the coil wire back on the distributor cap and check for spark at a spark plug. I would say the rotor fixes more than half of them