Hi All,

I have recently replaced my Ignition Amplifier and Coil with the Crane Cams XR700 and their coil. This was done due to what I believed to be a faulty coil (It was still the original!).

It has all been fitted in accordance with the diagrams etc.

I now have fantastic spark from the coil (Testing against the engine).

But I have no spark out of the distributor!

I got a second hand cap drilled an inspection hole and checked my timing. The Rotor is dead centre on cylinder 1 when the light on the amplifier is on.

Does anyone have any ideas?

 

A few things I have had.

1) Rotor is shorting to earth via the centre shaft.

2) The carbon contact brush inside the cap has fallen out (it happens) or is worn away (that happens also).

3) The HT lead from the coil to the cap is DUD.

Apart from that, there is not much else, since you got ZAP out of the coil, that HT lead, carbon brush, rotor is about all that is left.

 

Thanks for that.

I have already replaced the HT Lead and the Distributor cap.

I had never thought that the rotor could earth out within the distributor?

How do you check for that and much more important how would you rectify it?

Cheers

Steve

 

Basically with an ohm meter, and connect one probe to the brass strip, and the second probe on the underside where that metal spring clip is inside the hole that goes over the shaft, and you MAY get a reading, I did NOT.

That "high voltage" from the coil is a fickle thing and can find its way to earth in the most unlikely places, and an ohms reading may not always be detected. I just had a "gut feeling" on the PreHE that the rotor was earthing, so replaced it.

My suggestion would be to replace that rotor with a new one, as they do wear out, particularly the tip from all the arcing. A new cap should ALWAYS have a new rotor.

Make sure you get the correct rotor with the magnet in the heel that operates the fuel injection system.

Some new caps are also a bit suspect, and when installed the tip of the rotor is "below" the contacts inside that cap, so the rotor has to "arc upwards" to do what it does.

I have had this a few times, and cap brand/supplier makes little difference. I have installed mine (HE) without the gasket, and the arc marks are 2mm up from the bottom of the contact probe, and is sweet. The other one has 2 fibre washers (1.5mm thick each) inside the rotor to raise it higher on the shaft, and is fine. It is pretty much one for one on this rotor alignment I am afraid.