what causes this?

[bmcecosse]

I too would expect the HT circuit to be in the Mohm range - but I have never measured it. No need - it's 'never' the coil !!
Edit - looked it up and indeed it should be 7.5 to 10 Mohm

Throw away that 'Classic' book......

[davidmiles]

Thanks for that Bob, you are a fountain of Knowledge Sir. I will go through your post line by line later on. In the meantime my parts arrived from ESM, new Rotor arm, leads, spark plugs, (and while I was at it I swapped the air filter over for a new one too). But alas with all that fitted there was no change. I took off the petrol pipe from the carb and on a turn of the key petrol squirted in to my glass jar, I checked the float needle and that was free moving, fuel in the float chamber. I pushed the suction piston up and down from the air breather hole to see if there was a needle blockage, still no joy on startup. So tommorrow morning I'm going over the low tension system to see where the fault lies. The Distributer model is the Lucas 25D electric model, thanks for looking that site up Bob.

[MarkyB]

I just tested the coil that is living on my mantelpiece.
If the readings for primary and secondary were reversed it would be fine .

[JOWETTJAVELIN]

Don't know what all this bother of testing is about; if it works bung it on the car, if it doesn't then lob it.

[MarkyB]

The one on the car is fine, the one on the mantelpiece was a freebie and an unknown quantity, simples!

[Alec]

Hello David,

as it is electronic ignition I'm assuming your car is negative earth; with the ignition on you should read about 12v on the +ve terminal of the coil with the ignition on, if not then there is something wrong with the feed from the ignition switch. If you have 12 v, remove the king lead from the centre of the distributor cap and hold it close to earth and crank the engine to check for a spark there. If there is then the electronic module is working, if not it is likely to be the problem. If there is a spark, replace that lead and check for a spark at the ends of the plug leads. If no spark suspect the distributor cap as you have a new rotor arm? I'm also assuming that the leads haven't been disturbed since the car last ran and so are on the plugs in the correct order?

Alec

[davidmiles]

I've unplugged the lead from the distributer cap centre connector, so the lead is attached from the coil one end, and to the engineers tweezers held close to the forward lifting eye, I could see from the drivers seat when I cranked it over there was no spark at all coming from the lead to the lifting eye.[frame][/frame]
So with the multimeter in the 20 volts range, (the next one down is 2v) I only got a 4 volt reading with the ignition on and the probes on the positive and negative terminals of the coil. Could be the battery is low after all this teating, I'll check the battery voltage next, But it still turns the starter motor over well, so It can't be too low. Yes it's a neg earth vehicle by the way.

[Alec]

Hello david,

the voltage across the coil does not say very much as the electronic ignition module is in circuit. What is important is the voltage from the coil +ve terminal to earth. However assuming the supply to the coil is healthy, I suspect the electronic module. Have you any points and a condenser to replace it with to try again? Alternatively, disconnect the wires off the coil negative terminal, and using a short length of wire connected to earth, switch the ignition on and touch the -ve terminal briefly with the end of the temporary wire, if your king lead then sparks (in the position you showed), however weakly, then it's definitely the electronic module.

Alec

[bmcecosse]

Check the HT connection at the coil end - and is that bracket bare metal - not painted ? Wee bit hard to be sure in that picture. Also the gap there may be slightly too large - try to get it down to 25 thou or so.

[JOWETTJAVELIN]

The one on the car is fine, the one on the mantelpiece was a freebie and an unknown quantity, simples!

You're a lucky man. In our house with my car parts the furthest I've got is the conservatory, never mind living room. I am also regularly accused of having 'taken over the garage and the shed'.

However it means I can hide there safe in the knowledge I won't be disturbed.

[MarkyB]

Swings and roundabouts then, I don't get moaned at but I'll be sleeping alone tonight.

[kennatt]

I@m with roy on the gap looks too wide,after all its only designed to jump a spark plug gap,get it closer and try again before suspecting the coil.

[davidmiles]

well the new coil arrived from ESM this morning so I plugged it in and turned the key, there was a new noise, a kind of rumbling start with misfires,[frame][/frame]

[davidmiles]

so I'm not out of the woods yet, the startup was rough, I suspect I may have refitted the new leads in the wrong order on the cap. Here they are in the order 1 3 4 2 one being the cylinder nearest the radiator, but are they correct on the cap? Ive numbered them so you can see what lead goes to what cylinder[frame][/frame]

[davidmiles]

fitted to the dizzy the numbers are like this. is this correct?[frame][/frame]

[chesney]

Try moving each one back 1 anticlockwise. That's how they are on my moggie, but my timing and your timing could be two different kettles of fish!

[katy]

The distributor turns counter-clockwise, you have the leads set for clockwise rotation. Interchange #2 and #3 and you shoud be good to go.

[mogbob]

David
Katy is spot on, Firing order should be 1,3,4,2

Bob

[bmcecosse]

It is anti-clock rotation. Has this been the problem all along?

[davidmiles]

thanks Katy, the problem was the Electronic Distributer, I'm in consultation on the returns policy of the supplier, I'll update when I have a resolution. Thanks for your help everyone.