Elise S1 111S misfire

[magarnett]

I have a misfire on my 1999 111s S1.

Mainly noticeable below 2,000 RPM when under hard throttle in a higher gear (so under load) over 2,000 RPM seems ok.

Also sounds lumpy on start-up

Just for info:-

1. Coil pack changed 2 years ago, say 3,000 miles since
2. Magnecor HT leads fitted at same time as above
3. Original misfire detection unit and wiring disconnected when above HT leads fitted

I had it at a local Lotus specialist a few months ago and they seemed to improve it but only thing I could see that had done is reduce spark plug gaps from 0.9mm to 0.7mm it ran ok for a while but when I serviced it and replaced original gaps on the plugs it ran worse so replaced back to 0.7mm and it runs a little better but still misfiring.

Any suggestions?

Coil packs again?
HT leads?
Throttle position sensor?

Any help / advise welcomed

Cheers

Mark

[Tickle]

magarnett said:

I have a misfire on my 1999 111s S1.

Mainly noticeable below 2,000 RPM when under hard throttle in a higher gear (so under load) over 2,000 RPM seems ok.

Also sounds lumpy on start-up

Just for info:-

1. Coil pack changed 2 years ago, say 3,000 miles since
2. Magnecor HT leads fitted at same time as above
3. Original misfire detection unit and wiring disconnected when above HT leads fitted

I had it at a local Lotus specialist a few months ago and they seemed to improve it but only thing I could see that had done is reduce spark plug gaps from 0.9mm to 0.7mm it ran ok for a while but when I serviced it and replaced original gaps on the plugs it ran worse so replaced back to 0.7mm and it runs a little better but still misfiring.

Any suggestions?

Coil packs again?
HT leads?
Throttle position sensor?

Any help / advise welcomed

Cheers

Mark

I have just had a very similar thing fixed on my S1 111s, in fact your description sounds like what symptoms I noted on NORLOG

Tickle on NORLOG said:

Driving to Liverpool for cars and coffee a couple of weeks back and it started to splutter under load, not WOT just pulling away from junctions at anything more than a controlled slow drive off. The splutter coincided with the engine management light coming on and flickering in-time with the splutter. The tick-over also seems 'odd'.

I cleaned my engine bay a few weeks ago, my first thought was water had got in (I am cautious when cleaning the engine). I looked for any water under the plug cover and checked each plug recess for any damp with kitchen roll, they were all dry. I give it all a squirt of WD-40 anyway. Still no joy.

Spoke to Ollie and he mentioned the Misfire Detection Kit (MDK) is probably playing up, the best solution is to just remove it as its a recall fit from Lotus on the 111s. Has a search on SELOC and the MDK did sound consistent with what was happening.

I pick it up tomorrow night, I will report back on what work has been done.

[Tickle]

Well, I got my car back... problem is still there. It only became apparent on the way back so the car is now stuck at home. Looks like recovery van will be needed to get the car back to the garage!

Sorry I couldn't shed any light on your problem, I feel your pain though.

Edited by Tickle on Wednesday 21st October 19:31

[banx22]

Change the Magnecor HT leads for OEM ones. Apparently the Magnecor HT leads can give this kind of problem for some reason.

Also; check that the engine earth strap is corrosion free (no idea if this will cure it but it certainly won't do any harm). Do the one at the front as well.

Another thing to check is moisture in connectors. Do you park it outside? check the engine pay connectors, for moisture (disconnect them, give them a blast of WD40 or ACF50 and put them back together). When I removed my rear clam a couple of years ago; the miss-fire detector got damp (I left the clam outside for a few days) and it did the same thing until I properly dried it out.

Edited by banx22 on Friday 23 October 13:43

[Tickle]

My miss fire detection kit was removed and blue and brown sensors replaced earlier this week. Speaking to the garage the next steps for the weekend are:

Check everything is dry (should be as kept inside),
Leads,
Coil Pack,
Lambda

Should be sorted for Winter... bugger!