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MG Midget and Sprite Technical - Electronic ignition issues

I recently bought one of the Powermax ignition kits from simonbbc and had the mechanics fit the electronic ignition, adjust timing and tune at the last service. Supposedly, they just replace the points system but the mechanics said they had to drill new holes? I had already fitted the new cap and rotor, and new HT leads about 3 weeks before fitting the electronic ignition component, and it worked really well.
Anyway, I am thinking of going back to points! Since the conversion, I now need to keep the choke out until the car is fully warmed whereas previously, I only used the choke to start the car when cold. The car seems to have less power, occasionally misfires and backfires through the inlet manifold/carbs, and seems to be missing/rough when cruising. I have no problems/issues whilst accelerating, and actually the electronic ignition is better when under full throttle.
Is this how electronic ignition units are supposed to be, or is it likely that I have a faulty unit or poor fitting? The mechanics comment about drilling new holes worries me.
Steve Travis

No, it shouldn't be like that. Some possibilities:

1. From what you describe that they have done, it sounds to me as though they have not set the timing correctly. this would give the symptoms you describe.

2. If the new holes they had to drill were for the module mounting, and they got it wrong, then the activation of the module by the trigger could be affected.

3. Another cause (though there is no indication from your post that they did any work which might cause this) could be that there is an air leak causing it to lean off. However, I would expect that it would be rough at idle in addition to the symptoms you describe if that were the case.
Paul Walbran

Just as Paul said.
They f#cked up.
Our B is on the same ignition for 2 years now and it is more economical has the same amount of power as before and shows non of your symptoms
Onno K

Okay, so maybe I should have had a good look earlier. I have been driving the car for a week, with the issues described. And, idle has been a bit rough.
I just went and inspected the distributor, without really knowing what I was looking for, and discovered 2 possible causes.
1. The tube/hose connecting the distributor vacuum advance to the back carb had come off! I re-connected it. Simple things.
2. There was a cable tie around the wires to the ignition module, on the outside of the distibutor cap, which may have prevented movement within the distributor. I recall reading somewhere that the cable tie is supposed to be inside the distributor cap, to stop the wires pulling tight? Anyway, I put another cable tie on the wires, this time inside the cap.
After these two changes, I went for a 15 minute drive and everything seems much better.
Is that likely the cause? Do I now need to have the timing reset/re-assessed?
Steve Travis

Leaving the vac connection off the distr creates a very lean mixture and causes the problems you described.

If it feels fine than this was it.
Onno K

Agree with Onno, should all be good now.

My son chased a problem for ages with his metro turbo, renewed fuel regulator and other bits, then discovered a leak in the vacuum line to the fuel regulator - new vacuum line an it was all good. Simple thing but it screwed everything up.
Paul Walbran

This thread was discussed on 19/03/2012

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