No spark at plugs

After reading through the posts to date the only thing to cross my mind was have you got a good solid earth lead between the block and the battery neg terminal?

Chris

In message , shazzbat writes

Hello Steve, Thanks for taking interest, I'm most grateful.

I can't see any problem with spindle, it turns as it should and the whole thing looks to be in clean and sound condition. It is difficult to say if the parts I have match the original spec for the engine . All I can say is that my new parts do match in part No. ,visual appearance and in close dimension to the parts I removed . I now doubt that any of the old parts were faulty. Besides new points etc. I have tried electronic ignition (simple under the cap hall cell) and get a whacking spark from the dizzy end of the king lead-- nothing at the plugs . At the moment it is defying the laws of physics .

IMO, given it's sparking, the dizzy *is* moving, because the points are opening and closing.

I'd still suspect (along with most other people) of a sudden jump in the dizzy timing. It could be at the gear end, or the base plate is has simply slipped on the shaft, and is out by enough of an angle that you don't get a spark.

It'll need a strip down of the distributor to tell though.

Another posters advice of TDC on Cylinder 1, make sure the points are somewhere near opening. My bet is that they're not.

Pete.

Try the following.

Check the continuity of the cap by first connecting the king lead into its place in the cap. Remove the centre brush and tape the bare end of a lead (call this end A) to it and push it back into the cap. Then turn the distributor and see if you get a spark at the other end of this lead (end B). If you do, then the continuity is OK so far. If not, then the brush isn't making contact inside the cap to the king lead connection.

If you do get a spark at end B, then push a plug lead into a contact hole outside the cap and connect end B to the relevant contact inside the cap (maybe by just holding it there), and see if you get a spark at the plug end of this plug lead. If you do, then the rotor arm must be duff and you could test it by substituting it for the lead with ends A & B.

I hope this is understandable!

Rob Graham

Looking at the thread and the info you have supplied, ie good spark at king lead, new cap and rotor fitted, The sudden stop and no start I would follow up on Pete Smith's suggestion, ie a slip of the shaft so that the rotor, when there is a spark, is not opposite a segment on the cap.

Simple test to see if this is the problem, remove D Cap and see if you can turn the Rotor arm. There should be a little "sprung" movement because of the centrifugal advance/retard, but see if you can actually turn the rotor shaft. If so then something has gone wrong between the cam gear and the rotor arm.

Graham

I had the chain drive sprocket strip on an old car where the engine stopped, although when checking there was a spark and the rotor spindle 'appeared' to be fine!

In message , mike green writes

Hi Thanks to everyone who replied to my question .

It was the rotor arm!

The first replacement rotor was a dud and threw me completely. No sign of a fault but totally useless. The second was fault free and the car started first time. Thanks again for your help. Regards

Most rotor arms are simply a strip of brass in a plastic moulding. Was the locating peg in the correct position? Because they're not all the same despite looking so from the top.

In message , "Dave Plowman (News)" writes

Yes, exactly the same part .

The main thing is the car does run now.

ISTR someone on the classic car newsgroup talking about a batch of faulty rotor arms causing all sorts of consternation up and down the country a year or two back. Damned if I can remember what cars they were for though.

Still of interest to know what caused the rotor arm to be faulty? The obvious answer is that it was tracking the spark down to ground ie the cam. But there's usually signs of this.