My a12 motor was running perfectly until the other day when it started to jolt and buck as though it was skipping sparks. It would run for a little bit but only if I was giving it extra fuel and now it won't start at all.. It tries and sounds like it is getting the average spark but won't kick over properly. I've put new spark plugs, leads, distributor cap, coil, bypassed the ballad resistor, changed relays, fuel pump and fuel filter but still tries to kick over but simply won't start. Any suggestions???

Has it got fuel out of pump? Try cleaning earths and also pos battery cable connections.

The bowl is at the right float level on the glass so it is pumping fuel and the spark plugs were wet just after turning it over. I will try the earths and cleaning connections

it's definitely not a carby issue?

Sounds like it needs new points & condensor. Supposed to be changed every 12 months

I agree with ddgonzal. Sounds like a points issue.

Condenser is already done may have to do points though. Cheers

It "bucks" so it is getting spark and some fuel. As it then fails to start, begin by checking its timing with a timing light.

You have now performed an easy test which results in a quick clear answer which will usually either find the problem or tell you the ignition is ok.
[Note that an intermittent connection to the coil, points or ballast resistor can keep it from starting even if timed properly.]

If its ignition timing is ok, and the wiring is ok, then move on to other things which could be wrong.

You could put some fuel on a cloth around the aircleaner, and if it starts and runs a few seconds you have found a fuel problem. This procedure is dangerous, so do it outside and have a fire extinguisher there(preferably C02 as that does not dirty up the engine).

Have tried the start motor in a can that you spray into the carby to start it and that hasn't kicked it over.. Will do the points if not then I'm going to do a compression check

yes do the points, then check if the anti dieseling solenoid is wired up correctly.

http://datsun1200.com/modules/mediawi ... p?title=Anti-diesel_valve