emissions

[auditor]

Hi, I'm trying to sort out my dad's m100. It's failed its MOT on emissions. He mentioned that he'd read about a chip that Lotus developed to cure this problem. I've so far not found any mention of this looking around.

Can anyone tell me if this exists and if so where I can get one?

Thanks, Jon

[HJ2]

Hi Auditor,

Try the search engine and look for "closed loop conversion"
That'll give you enough to start with.

Oh... nothing wrong with your dad's memory!
Regards from the Netherlands and good luck!

[auditor]

Thanks for that. So it looks like a closed loop conversion then.

Just put it in simple terms for me. It's a 1990 SE, stock as far as I know. This means I will need:

An everest closed loop chip

A new oxygen sensor

Have I understood this correctly and is Rockauto the place to go for both?

Thanks again, Jon

[ailwyn]

Auditor,

I take it you have tried adjusting the "CO Pot"? It's a device near the ECU which can be turned with a screwdriver to adjust the emissions control - needs to be done while hooked up to an emissions reader. I can't give any more detail than that as my Elan is closed loop and relies on the O2 sensor.

It's not the closed loop conversion that your Dad is thinking of. Lotus issued a revised "9930" (hope I have the right number) chip which gave better control to the "CO Pot" which controls emissions on non-closed loop cars. Best bet there is to contact Lotus to see if they have any (free or cheap) spares, other than that you could go the closed loop conversion as you have described, or just get a 9930 mountain (or normal chip) from ESM (a member on this forum, creator of the mountain chips).

Rockauto can do an O2 sensor, but chips can only be had from ESM.

memberlist.php?mode=viewprofile&u=4 here is a link to ESMs profile which in turn gives you links to PM (private message), email, or visit his website.

Ailwyn

[HJ2]

For the Everest: Look at the top menu on this site, and click "mountain chips" The O2 sensor can be found on rockauto.
Since i have an S2 wich is already closed loop, the rest is abracadabra for me...

[GeoffSmith]

Ailwyn's correct - the 9930 should cure the open loop problem (see manuals or ESM's site for the service bulletin) although Lotus did not have any some time ago. A 9930 chip from ESM should effect the same result however if you don't want to go closed loop (there have been some issues) - the safest bet would probably be to get a combined open/closed loop switcher setup.

[RayD]

Jon,

To my knowledge 1990 SE’s can pass the emissions test with the original equipment fitted.

It’s not the case that each one of them has had to be modified to get through the MOT.

It might be better to post the recent history of the car, it may be something simple.

Ray

[theelanman]

depending on how much you want to spend.....
I'd start with the CO2 pot......then move onto the chip.....
although if youre doing the chip you might want to think about the brakes
cheers
G

[BFG in the BRG]

No doubt I shall get shot down in flames by someone more knowledgeable in these things, but I thought the emissions became more stringent some time after 1992 - which was my manufacturers brought out catalytic converters, and our cars were therefore exempt from the more stringent requirements - mine never had a problem getting through - so either - the garage may be applying the wrong emission test requirements, or there may be something else - might be worth getting it tuned and solving the problem before going down the closed loop route.

Besides going closed loop can be simple or can take a while and be a little frustrating. It appears Lotus put all the relevant wiring in place on some (like mine) whereas others (Bob Brown IIRC) had some of the loom missing and so had to partially create a new circuit - this involved removing the wheel arch liner and doing a handstand in the footwell - not at the same time I might add - it's all on the "Closed loop better fuel economy?" thread.

Dunno what others think but it might be worth connecting it to an Elanscan to see what's what and comparing/posting the results on here - there again I guess time is of the essence so just go for the tune-up.

If you don't have an interface there will nodoubt be someone nearby who has one - or I can pop mine in the post.

Hope this helps

[DaveB]

Agree with Ray ... should not need modifying to pass...

Just a quick question... but I am sure your MOT tester is better than the one I had.. ... Your guy is plugging the CORRECT vehicle details into his MOT test equipment.... mine spent half an hour trying to get my emmisions down to that of a catted car !!



...berk !


David

Edit... I see BFG has the same idea!

[RayD]

If you don't have an interface there will nodoubt be someone nearby who has one - or I can pop mine in the post.

That's a kind thought BFG.

MickMick's car failed on emissions seemingly because it hadn't been driven, or run up to temperature prior to the test ... It had been parked up and cooled down about 30 feet away from the test ramp. The only thing he did in preparation for the re-test was take it for a run.

Ray

[Fetnas]

I've just batteled through this problem myself. I also have a 1990 SE so you're probably in the same position.

It was blowing around 7% CO. The level would only come down when the mixture was dangerously lean. Part of the problem was the engine temperature sensor going out of range. This made the ECU think the engine was colder than it actually was making it run in the warm up mode resulting in a rich mixture.

After changing the sensor (only 15 pounds as it's used in many GM cars) the CO adjusted down to 1.5%. I did also had to sort out a small oil burning issue but it's unlikly you have the same problem, these engines shouldn't burn much oil!

If you need a replacement sensor, I picked mine up from Simpson supplies as that was the cheapest I could find, I think the part number is in the WIKI.

I hope this helps.

[auditor]

Thanks for all that info guys, things are becoming clearer.

I think I'll try and take it to a test centre where I can stand around and offer "helpful suggestions" and adjusting the Co2 pot to start with. If that's no good I'll try a new oxygen sensor and go from there.

The car will likely be for sale once it has passed its MOT due to my dad's ill health. It's been a lovely car but it won't be used so best for someone else to take it on.

[ailwyn]

If that's no good I'll try a new oxygen sensor and go from there.

You neither have nor need an O2 sensor unless you are doing a closed loop conversion (which you will never need to do).

[BFG in the BRG]

The oxygen sensor fits where I am pointing

oxygen sensor blanking plug (2).jpg

If you have a blanking plug like in the photo you do not have an oxygen sensor fitted