Lotus Elan

Loose ignition lead

PostPost by: alaric » Sun May 15, 2022 6:03 pm

Hi. On removing the carbs I found that one of the ignition leads was only just still plugged into the distributor cap. I just wondered if that might explain a miss that occurs once the engine is fully warmed up on the road, which only occurs as I press the accelerator. I'm wondering if this could be due to a weak spark on one cylinder?

Sean.
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PostPost by: billmoore42 » Sun May 15, 2022 8:40 pm

Yes, I had the same issue several times with my side entry screw in 23D cap, if one lead it loose, it invariably leads to misfires and poor running. If you have carbon core wires, you might want to consider upgrading to solid core wires, as in my experience, the carbon core wires tend not to connect as positively to the screw in style side entry cap. Regardless, it would be a good idea to remove the cap, cut off all the wires 1/4", and then affix them to to the side entry cap again.

I got the very pricey Magnecor wires part #4790 wires a year ago, which have a more robust core, and no more problems with the screws losing contract.
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PostPost by: Baggy2 » Sun May 15, 2022 9:02 pm

+1 for the Magnecors . Using carbon cored leads I used to have trouble with plugs getting fouled. Tried different makes and temperatures of plugs without success, Switch the the rather expensive magnecors and not had a problem since - Hope thats not tempting providence !
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PostPost by: alaric » Sun May 15, 2022 10:12 pm

Thanks. I have 8mm Lumenition performance Silicon leads on the car already. The issue is the loose fitting of the leads to the distributor cap. The leads plug onto the cap and are oriented downwards, and it doesn't take any effort to pull them out. So with the country roads down ere in rural dorzet, I think I've shaken one of the leads loose. I will be looking into how to fix them in permanently, having no need to ever unplug a lead from the dizzy. I was just wondering if this might only show up once the engine was thoroughly warmed up - if it could then hoorah it's a simple fix i.e. is a better spark needed on a warmer engine - can't see why it'd make a difference myself, so I wondered if others had found this. Trouble is I can't test it now, as I've removed the carbs to get to the ignition. Which reminds me, how do you do up the lower carb flange nuts and get the thackery washer gap to 1.02mm? Seriously.... my big mits just don't fit in there. I managed it on my old +2, but maybe I didn't have the coil in the way - I think I reached under the carbs and got two hands on the nut and washer.

Sean.
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PostPost by: StressCraxx » Mon May 16, 2022 2:54 pm

If the metal clips become loose over the terminal, the clips can be squeezed slightly with pliers to make them snug on the terminal. One can also use small zip ties sung around the plug boot to help keep the boot in place.

Eventually the plug wire clips become fatigued and it's time to replace the plug and coil wires with new.
There is no cure for Lotus, only treatment.
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PostPost by: Andy8421 » Tue May 17, 2022 5:58 am

Slightly off topic, but I have no faith in modern fangled resistor cables. There was a thread about this some time ago (which I can't now find).

I use copper cored cables (no problems with connections at the dizzy end, either with a screw or clip fitting, and a good quality resistor plug cap with good seals at the other end.

https://www.gsparkplug.com/1x-ngk-resistor-spark-plug-cap-sb05f-red-8567.html?gclid=EAIaIQobChMIpfSx-ezl9wIV0uvtCh0Vig-yEAQYASABEgJytfD_BwE
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PostPost by: alaric » Tue May 17, 2022 10:37 am

Aha, that's what I need - screw or clip fitting at the dizzy end. I'll have a look for that sort of cap. For the time being I'm moving my coil up onto the wing, so that I can reach under the carbs to fit them, and will also then be able to get to the dizzy more easily. It's my big hands that are the problem... need more space.

Thanks.

Sean.
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