Ignition Woes

[colinc]

I hope someone out their can return some sanity to my household with some help/advice.

90 Excel SE off road 2yrs. Back running last Sunday - ran perfectly for 30mins or so.

This week won't start due no spark.

Traced back to coil from which there is no output but there is resistance to ground and between + & - terminals that checks out okay

Checked all connections (using continuity /resistance tester) to/from ignition amp and appear fine (previously had the common fault with pick-up coil connector and I've previously fixed this and now rechecked again and again).
Checked earthing to everything (coil; ignition amp). Some a bit dodgy but everything cleaned up and rechecked but still no spark.
Then tried binary search to narrow down fault a bit more but got stuck straight away with pick-up in disi - what should you expect by way of output? I have basically nothing irrespective of position of disi.

This is really annoying especially since it was running fine after lengthy lay-up just a week ago!

Any help suggestions most welcome

Thanks

[Lotus-e-Clan]

Have you tried the time-honoured trick of disconnecting the rev limiter. It can be a troublesome beastie apparently...perhaps it is preventing any output from amp to coil? I'm not 100% sure how it works on the Excel as I've never had to play with mine because it's never let me down (touches wood). Fractured ignition amp wires is another common fault.

Someone will be along soon with real Excel ignition problem solving experience no doubt.

[BillB]

Colin

Sorry to hear you're having trouble.

Check out my posts on http://www.lotusexcel.net/phpbb/viewtop ... f=2&t=2765 if the rev limiter doesn't sort it out.

My fault only affected one cylinder at full vacuum advance.

Good luck

Bill

[terry]

TRy this, the lead between the Ign. amp and the dizzy is a bit "floppy", and sometimes breaks in the middle.

start the engine, but get someone to move this wire around, if it starts then dies when you move the wire, replace wire.

Terry

[barker_001]

I had a similar problem last year, and in the course of solving it, found a number of faults in the ignition system:

1. As Terry mentioned previously, the silicone insulated wire from the distributor breaks down inside, giving an intermittent open circuit. I cut the wire right back inside the distributor, and replaced it with fresh silicone wire. I also replaced the connector between the distributor cable and the short black cable which runs to the AB14 ignition amplifer. If you measure the output of the distributor as you turn it by hand, you should get a pulse on the meter as each peak on the rotor passes the reluctor pickoff. I can't remember exactly how much, but it was a good couple of volts - easily measurable.

2. The input connector from the distributor lead on the AB14 amplifier was corroded - cleaned it all up.

3. One of the spade connectors to the coil had "missed" - the spades weren't actually mated, the male spade was just slid inside the insulation of the female one. The result - an intermittent contact.

It started first time once I put that little lot right! Hope this helps...

[colinc]

Thanks for all the advice everyone. I'm away over Easter but will give it a go when back

[colinc]

Hi All,

Pleased to say problem has gone away - as suggested broken wire inside disi (wires from pick-up).

I can now report that you should see a little under 3.3Kohms resistance at the end of the wires that go to the ignition amp (ignition off, wire disconnected from amp. Also note this does not change at all regardless of engine position, its a current device I think) - might be useful for anyone else who has similar issue.

Anyway thanks to everyone for advise. Now off to get new exhaust and MOT