free hit
counters
back to the future... points? - Engine/Ancilliaries - The Lotus Forums Jump to content
simon a-b

back to the future... points?

Recommended Posts

Hi all,

I've got lumenition on my S3 and have been chasing intermittent poor running for ages. I'm considering putting points back in to remove the lumenition as a potential cause of the fault. 

Any opinions on this course of action gladly received!

When I bought the car it had points (from the car history retrofitted) and I removed them and fitted the lumenition. The car ran fine for many hundreds of kilometers, including use as a daily driver. 

The issue I now have is really poor running, caused by badly timed spark. When it's running poorly if I fit a timing light the timing is mostly spot on, then when it hits this intermittent issue it is all over the place. The distributor isn't moving so I suspect the module, but they're pretty expensive to swap out if I'm wrong (and being solid state I'd think they are unlikely to malfunction, more likely to work/not work)... so my thought of points again.

I'll need a set of points, a condenser, and anything else? I remember having to set the gap on the points, they are not adjustable within the distributor relative to the shaft though from memory? They sit on a pin and then you adjust the gap, and time it as usual by unclamping the distributor and rotating the whole unit?

I'll dig up some simple wiring diagrams of points ignition off the web, and hopefully do the swap later this week.

Cheers,

Simon

 

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

From the brief look I had on google at pictures of the Lumenition system (as I'm not familiar with it) won't you also need a distributor vacuum capsule (for ignition advance?) and the points mounting plate which fits inside the distributor?

It is possible this plate is still in the distributor. I can't tell from the photos I have seen.


All we know is that when they stop making this, we will be properly, properly sad.Jeremy Clarkson on the Esprit.

Opinions are like armpits. Everyone has them, some just stink more than others.

Share this post


Link to post
Share on other sites

Think I recall an owner or two changing to full electronic ignition modules and documenting it on here?

either way, good luck, and I'd be grateful if you could post your resolution, as I may have a similar issue soon ?

Edit, just had quick look... This thread seems fairly relevant to us...

 

Share this post


Link to post
Share on other sites

Check the distributor bearings..if the shaft is wobbling that can cause it...also the advance and retard springs and counterweights...they can do weird things too.  Means taking the distributor out, though.....


Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

Share this post


Link to post
Share on other sites

Its also worth cleaning the optical sensor. Check oil is not leaking into the distributor. Check the connector for the sensor.

Make sure nobody has wired-out the ballast resistor (this was done on my car which is one of the reasons the PO sold it as it had an intermittent ignition issue and I bought it knowing that there was a problem to investigate).

There doesnt seem any benefit in replacing a Lumenition system with another which still uses the distributor. On the Excel I used to own I threw away the distributor and installed a system triggered by tiny magnets mounted in holes drilled in the back of the crank pulley, and a sensor which screwed to the engine. This was from www.sdsefi.com. Nobody else seems to use this system though, the other systems available use a toothed timing wheel and a sensor which appears more difficult to install but would still have the benefit of no more distributor misery. 

Share this post


Link to post
Share on other sites

I'll do my due diligence on the distributor... How hard is it to take out? and will it only go back in one way? It barely idles so I wouldn't think the advance/retard mech could be the problem?

The ballast resistor is in there, mine had been removed too so I added it again. Really annoying that it ran so well for so long and now this! the joys of the Lotus...

Share this post


Link to post
Share on other sites

Its a bit fiddly to take out. Easier if you have a compact geared starter motor fitted as this leaves more room.

If you mark it, you can get the timing fairly correct when you put it back in. Also mark the position of the shaft so you can put it back without having to turn the shaft too much to engage the drive back in.

Share this post


Link to post
Share on other sites

The drive dog is offset, so it the shaft only fits in correctly...there is a coil spring that pushes the distributor out as you undo it. The distributor itself has to be rotated to get the timing spot on. Marking the distributor and the engine so you can align them accurately helps.  


Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

Share this post


Link to post
Share on other sites

Useful info above , thanks all. One addition to the offset dog info:

Just put mine back in following the manual's precedure to set at 10deg BTDC, and ended up with the dizzy 180 degrees out, so the cable exit hole was pointing upwards which seemed wrong, and the rotor arm was pointing to #4.

I then realised that the ingition sprocket turns twice for every crank revolution, so another turn brought it back round to the right dizzy position, where the slot in the drive spindle is offset to the right of centre, and #1 rotor lined up as it should.

 

Share this post


Link to post
Share on other sites

Dave,

I fitted Lumenition to an S1 Elan and ran it hard for 12 years without fault. Solid piece of kit in my experience.

Steve

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...