Im almost embarresed to ask for help on this subject, as I don't think you could get a more simple ignition system, but sadly my generation has grown up with CDI 's and coilpacks and im just not sure where to start.

The old man has bought himself a classic 60's trackday car, It is powered by an incredable spec BMC B Series engine someone has clearly spent a fortune on it,

The problem is simply that I can't get a reliable spark from it, It has got a distributor but the black that goes from the distributor to the coil goes through a very early luminition timing box with rev limiter(the status led on this box does not come on).

The outcome is a very weak strangly timed intimitent spark. enough to fire ocasionally but not run.

If I run the black wire from the dizzy straight to the coil then there is no spark at all.

If I put this black wire thru the luminition timing module, I get a great spark on number 4 plug but only when you key on and off but not when cranking

The lucas coil has 3 ohms across it and 12ish volts.

So I guess it must be either the points or the compensator capacitor (is the right name) in the distributor.

So I really just want to see how the engine runs, I want to remove the luminition module complication, can anyone suggest what is probaby wrong.

Thanks for your help in advance

compensator capacitor - I think you mean condensor.

I'd get a new condensor and new points and fit them as a matter of course - they're pretty much peanuts cost-wise.

this black wire thru the luminition timing module, I get a great spark on number 4 plug but only when you key on and off but not when cranking

That would indicate to me that perhaps the first place to look would be the points gap - if it's permanently closed (or close to) then you won't get a spark.

Get the feeler gauges out!!!

Alternatively buy an optronic kit for the dizzy and fit electronic ignition

[Edited on 3/4/09 by stevebubs]

Points...now that takes me back. Once upon a time I fitted 2-3 sets a day. Can't remember the last time I did some.

1. Always fit a new condenser with new points.
2. Make sure the contacts are clean and dry (some have grease on them when supplied).
3. Set them with clean feeler gauges.
4. Don't put feelers through points that aren't new. The worn faces mate up and won't once you push feelers through.
5. Grease the cam...but not too much.
6. Once set and running check the dwell angle (angle turned with points closed). Adjusting is trial and error till its right. Worn dizzys have play and the static feeler setting isn't reliable.
7. Reset the timing after.

adrian

(1) Check the wires to the points are connected to the spring arm the right way.--- very common mistake on both types of Lucas points of this era.
If nut and bolt fitting connector can be fitted on wrong side of insulator.
If clip on fitting connector can be fitted upside down causing a short.

(2)Check the condenser mounting screw is tight on the base plate.
(3) Check the points gap on each lobe of the distributer cam -- this shows up bent distributer shafts or badly worn distibuterss Lucas distributer points gap should e set to 0.014" to 0.016". (ie 0.35mm to 0.4mm)

(4) If distributer has a vac advance -- remove base plate and check earth on underside of base plate.

When we used to sell those points to DIY mechanics on a Sat we always said "See you Mon" as they left! Thats when we move the wire to the right side of the insulator or turned the connector around.

Happy Days!

adrian