Lotus Elan

No spark

PostPost by: Uboat » Wed Jul 29, 2015 11:08 am

Hi,

I have no spark in plugs. This after changing to a new starter (now works excellent), and refurbishing my tacho (haven't got any rpms yet so I can't see if it works).
I have measured voltage at the coil poles, and they are 11,5V on positive and 1,0V on the other.
I have a pertronix electric ignition. Plug cables/plugs are ok.
Why is this? Could it be a short circuit in the tacho, or is it the distributor?
/Ulf
1974 Lotus Elan +2 130/5
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PostPost by: nmauduit » Wed Jul 29, 2015 12:23 pm

Hi,

as a partial reply to your post, RVI tachos have the ignition low voltage signal through them, so there is a possibility of a short which would translate in no spark... I believe there are a couple variations of RVI tachos, bottom line being that a white wires in the lotus dash loom would do a loop around a piece of soft metal that would convey the coil input current inside as a sensor. So in case you have these 2 white wires make sure both are connected to the tacho, or if you want the tacho out for test purposes have the 2 white wires connected to each other.
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PostPost by: john.p.clegg » Wed Jul 29, 2015 12:54 pm

Ulf

11.5V on one side and 1.0V on the other sounds good,but do the figures change as you rotate the engine?

John :wink:
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PostPost by: Galwaylotus » Wed Jul 29, 2015 7:05 pm

Is your static advance set correctly? When I converted to electronic ignition I had to guess at a static setting. I kept rotating the distributor until I heard a "cough" then moved it a bit more until the engine would fire. I knew my plugs were firing as I put an inductive timing light clamp on the HT leads and cranked the engine while looking for the light to flash (it did!).
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PostPost by: LI-599 » Fri Aug 07, 2015 9:45 pm

Hi, I had similar problems with 2 Pertronix units and fortunately had the original Lucas unit to keep me going till I bought an Accuspark dizzy. My local mechanic said early Pertronix units were reliable but had questions about latest type.
Cheers, Ian
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