no spark at plugs

[bleddyn]

have put test bulb on coil,and thats ok,but have one of those magnatronic
cartridges instead of points,have tried a bit of everything over the 2 weeks and because there is no points or condenser cant check at that end,so wondering is it worth changing back to points, also moggy neg earth and have i got the leads to coil right way round for neg earth, have taken plugs out and turned her over, no spark from 6mm as suggested by manual, though plenty of smell of petrol, so can anybody help, also dizzy cap does not show signs of tracking, had prevously had problems after 8-10 miles of missing,and not starting when warm, but now seemed to have lost everything [spark wise], dont really want to take to garage, but if needs must'''', have always worked on moggies, and have always soughted things out my self, but this one is baffling me, also is it straight forward to replace the points, or will i have to alter the timing etc, all suggestions gratefully received thanks

[katy]

Suspect the coil. Do you have a spare you can swap in for triers? Or borrow one from a buddy?
Do you have a multimeter that you can check the coil with?
The coil should work even if the wires are connected opposite. Are there markings on the coil, beside the terminals? If it's marked + and - , the - should be connected to the distributor. That's with points, don't know about the magnatronic.

[MarkyB]

All the points do is make and break the connection from the coil.
You can easily replicate this by earthing the wire to the distributor.
If you get a spark from the coil when you do that have a very hard stare at the magnatronic unit.
Is it earthed properly? is the rats tail from the points plate to the distributor in good nick? Is there a good connection between the points plate and the distributor body?
If all the earth connections are good the unit has probably cashed it's chips.

[bleddyn]

have changed the coil, when checking with test bulb, +&- lightup bulb,when you say earthing the wire to the distributer,do you mean removing the ht lead and touch to earth,thanks

[MarkyB]

No, that is the wire from the distributor.

Unplug the HT lead that goes from the coil to the distributor at the distributor end and lay it on the engine away from where your hands will be then turn on the ignition, take the small wire that goes to the distributor and drag it across the metal part of the distributor.
You may some small sparks from that wire (which are harmless) but you should also see some fat blue sparks from the HT lead (which aren't harmless).
Fat blue sparks mean the coil is fine. No sparks or feeble yellow sparks are less good.
Let us know how you get on.

[bmcecosse]

That's the trouble with electronic ignition - when it goes wrong - it's difficult to fix. I would go to points. But - how did all this problem start ? What were the first symptoms? Have you tried just fittiung a new set of plugs ?

[mike.perry]

Check the carbon brush in the top of the distributor and try pulling all the HT leads out to make sure that they are secure.