New electronic dizzy - no spark

Happy Saturday all,

Mine's not so happy. I have been having running problems with my '75 2.3 petrol. It would run well for a while but then die when it got hot. It would then be fine again when it had been sitting for a while. As per advice on here I tried a new condenser but that made no difference. Bought a new coil from SimonBBC to see if that would help but no.

So I decided to buy a complete electronic dizzy from SimonBBC. But I am getting no spark. I have emailed Simon so let's see what he suggests but I have been through his online suggestions to check when there is no spark.

So I have a few questions anyway that you guys might be able to help with:

1. is it actually possible to fit a new dizzy the wrong way round? My new one only fits with the rotor pointing rearwards at TDC and I have a feeling my old rotor pointed forwards when at TDC. Or maybe that's completely irrelevant since this is a new electronic dizzy

2. I tried the static method suggested by a few people on here (Like CharlesY albeit in 2009). With a spark plug attached directly to a HT lead coming directly from the coil I cannot get a spark no matter how much I turn the dizzy.

So I'm out of ideas now. Don't know if I've got unlucky with a faulty unit or if I'm doing something wrong. I'm prepared to admit that electrics aren't my strong point but this isn't quantum physics - all the points/electronics do is send a signal back to the coil to fire a big old pulse of electricity to the top of the dizzy at the right time. So if the electronic points are working then I should be able to find a spark with a plug directly connected to coil?

My only though might be that the dizzy is 180 degrees out but I can't get it to seat in if I turn the rotor 180...

Thoughts?

TIA,

Al

If the dizzy is 180 out then you'll get back fires that will blow the exhaust up! Trust me, i know.
The dizzy doesn't send a signal, it opens/closes the circuit. Coding the circuit energises the coil. The collapsing field caused by opening the circuit causes a spark
There should be 12v to the coil, a wire to the dizzy, which is then earthed. The (electronic) points make/break this circuit

Thanks Kermit,

So it should be possible to fit the dizzy both ways - mine won't seat when turned.

This design of electronic dizzy has two wires coming from it, a red that goes to positive terminal and a black that goes to negative. And the advice on SimonBBCs site suggests that the system needs the body of the coil to be earthed.

When I said send a signal I meant close a circuit yes. So in theory if you remove the dizzy from the picture by connecting a spark plug directly to the coil and then bridge the positive and negative terminals on the coil it should fire out a proper spark, yes? Wouldn't want to bridge that for more than a millisecond I guess otherwise coil would heat up too much. I'm not getting a spark when I do that though so maybe that points to a bust coil.

Anything else I can try?

Thanks,

Al

Flat 6 said:

So in theory if you remove the dizzy from the picture by connecting a spark plug directly to the coil and then bridge the positive and negative terminals on the coil it should fire out a proper spark, yes? Wouldn't want to bridge that for more than a millisecond I guess otherwise coil would heat up too much.

Click to expand...

If you connect a plug to the king lead from the coil and earth the plug body, then connecting 12v to the coil then you should be able to make break the coil negative wire to make a spark.
Don't worry about overheating the coil, you can leave it connected for minutes before it starts to feel warm. Just be careful and don't light yourself up. Old style could aren't like the modern ones that can pump out 40kv but they still pack a punch

Ha! Thanks for that warning! I got a pretty sharp jolt since last posting so I guess that means the coil is working! That'll teach me to hold the HT lead near the plug!

I looked again at the seating of the dizzy and the lugs are offset slightly so it looks like it can only go in one way. That removes the chance that I had things 180 degrees out. I've done everything I can think to do now so I'll wait to see what SimonBBC says on Monday.

Cheers,

Al