Electronic ignition

[AEX146]

I am thinking of changing the points in my Lucas DX6A distributor to an electronic contact breaker system.
I would be interested to hear of if anyone has experience with either the Lumenition or Petronix systems and get their advice.

Regards,
Ben Morgan

[Big col]

Hello Ben,
It really is down to your choice as both have pros and cons. I prefer the conventional setup after using electronic systems in the past and being let down.

Electronic systems are only as good as the electrical system in the car. If your voltage regulator isn't as good as it should be then the variable voltage to the unit could burn it out. If the unit fails then its time to contact a break down service as you are stuck.

Contact breakers are only as good as the maintenance given to them. Cheap parts can be more trouble than they are worth, especially the condensers. If anything fails, you can usually repair or replace at the side of the road and get going your self.

Both systems rely on all the other components being in good order, rotor arm Distributor cap, distributor bearings, plug leads etc

[AndyMay]

Both systems are fine enough when working, however as the previous poster suggested, such systems can be fragile and are susceptible to burning out through voltage spikes (or if you forget to disconnect whilst welding). Equally, you could go on years without issues.

On a previous vehicle (Lamborghini) that the previous owner had (unsuccessfully) converted to petronix, I converted the distributor to use Chevy HEI parts (reluctor, Hall effect pickup + separate HEI module). It was not a particularly difficult job and was really satisfying to do. This resulted in a very robust ignition with cheap but reliable OEM parts. It might be a consideration if you are that way inclined.

[AEX146]

Thank you for the responses.

The reason I am thinking about electronic ignition is that my Ace has become increasingly difficult to start, particularly if it's left unused for a couple of months.

The problem seems to be with the ignition rather than on the fuel side. There is a spark but it seems to be weak- if that's a thing! I've changed the coil (which was getting very hot), cleaned and set the points and changed the rotor arm but none of this has done the trick.

I thought perhaps that a fully electronic system would give a much bigger kick but the "123" system doesn't have the rev counter take off so the question is whether an electronic circuit breaker system with heavier duty coil would result in a sufficiently strong spark.

All advice welcome.
Ben

[B.P.Bird]

Ben,
When did you last change:
1) The HT leads - all 7 of them
2) The rotor arm - the original Lucas arms suffer electrical breakdown after half a century. Go for a 'red' type replacement
3) Sparking plugs - they do not last forever
4) Distributor cap - has yours developed cracks and consequent tracking
5) Contact breaker points - modern replacements are poor quality and of foreign manufacture. I find the tungsten contacts frequently oxidise and become resistive. Never used to be a problem, but it is now. Keep them clean especially if unused for a while. I find the spring blade on the moving contact is often 'soft' and has lost its spring tension. A bit of re-arching between finger and thumb helps
6) The contact breaker gap - sometimes difficult to set correctly if the distributor shaft bearings have worn and there is play on the shaft. New bushes might be needed.
7) The Auxiliary Starter carburetter settings - see page 21, 22 & 23 in the General Instructions
8) The Thermo switch which controls the Auxiliary Carburetter. These switches have been in place for 60 or 70 years now and you should at least check that the switch is closed contact when the engine is cold. If the contacts are oxidised and resistive then the Auxiliary Carburetter will not switch on. A quick check, ignition on, is to short the switch terminals with a jumper whilst listening carefully for the feint click from the solenoid which opens the Auxiliary Carburetter feed. You have to listen carefully, but it will be audible if the solenoid is working. The engine will start without the Auxiliary Carburetter, but it takes a while and needs a good battery. If you have an earlier car you can use the float ticklers to get a richer mixture, but best to have the Auxiliary Carburetter working properly.

For what it's worth AE 22 starts almost before the starter engages. This is with a completely refurbished engine and so, with a higher mileage engine and if the items mentioned above do not help, it might be time for a compression test.

The conclusion of all this is that electronic ignition will not help unless all the other ignition parts are working as designed. Which being the case you will not need the help of electronics anyway

Barrie