I'm running a non vacuum advance dizzy with my engine. To get the engine running i stuck a normal vacuum advance dizzy on there and it ran fine.

Now with the other dizzy on i cant get a spark. The condensor is attached to the terminal on the points and this is also attatched to the lead that goes to the - side of the coil. Is this set up ok?

I will go and get a picture now as im sure it will be easier to explain that way.

Its realy frustrating as it was running and now i have the proper dizzy set up for the tune of my engine and it wont run!!!

Heres the pic
Rescued attachment P1030392.JPG

I assume the black/green wire goes to the coil negative. If so all looks correct.

Can't see from the photo but you have checked the points open when on the cam?

David

The lead from the negative of the coil and the condenser should attatch to the moving arm of the contact which otherwise should be completely electricaly isolated from the dizzy, base plate, pivot post, etc, so that it only earths when the contacts come together. Sorry if this is trying to teach egg sucking but if it worked before then something is put together wrong. Do the contacts actualy open and close when the dizzy rotates? ie is the gap correct?

[Edited on 31/7/05 by Dusty]

Check it's not earthing till the points close as well.

Is the points gap ok?

Is the condensor ok?

The points and gap seem fine, i will have to get the electrical meter tomorrow and make sure its earthing properly.

Its annoying as when i sold an old pinto i put the wrong dizzy in with the bits for it, the bloke who bought it (splitrivet) was kind enough to send it back, he said he had it running on his engine so i assumed it was all set up ok.

Got the next week off work, so will have to call in some favours from the mechanics i know.

Have you fitted new points? if so try wiping a piece of clean paper between the contacts, some points had a coating on the contacts which sometimes caused a problem . Also the old Ford distributors sometimes had an earthing problem on the base plate . Make up a small lead about 3 in long with small ring terminals on each end attach one end to the screw securing points to base plate and the other end to the screw securing baseplate to distributor body . Also has yours got a small black box in line with the low tension lead ? if so bipass it . This should help reduce voltage drop across points.

Ive checked the connections with a multimeter, and i'm always getting an earth even with the contacts open. For some reason the wire that is connected to the - terminal of the coil is earthed even when disconnected from the dizzy, meaning that the coil is earthed, but not through the dizzy. Does this mean the coil is knackered (i hope not as its an expensive one). Or is this normal?

How i understand is when the contacts are apart they break the earth to the coil which released the current to make the spark. Right?

Its really puzzling as it worked fine with the other dizzy.

You're spot on with your earth theory, with the points open, the earth should be removed from the coil. When you say you are getting an earth on the -ve coil wire, have you tried disconnecting it from the coil to check if it is coming from the coil itself, it could be a fault in the wire itself. Disconnect it from the coil, and then check if the earth is on the coil -ve, or in the lead. The capacitor could be shorting, causing the earth to pass through it to the coil. try removing it, and then check there is no earth at the coil -ve,until the points are closed. Also with the capacitor removed you can check that the points aren't shorting by testing on both sides with them open.
From what you describe, it looks like something is shorting to earth in the dizzy.
Draw yourself a diagram of the points/ capacitor/coil, and just go through the diagram, checking for earth and live.
Good luck
Cheers John

[Edited on 6/8/05 by johnjulie]

Try disconnecting the coil - lead and running a wire from coil- to the distributor , if you then have a spark problem is in wiring , also try touching the distributor end of the LT lead to earth with a spark plug attached tp main HT lead and earthed plug should spark if coil and HT lead are OK