Emissions data
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- Lotus-e-Clan
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Re: Emissions data
You should be able to smell the incomplete combustion of 5.8% CO (12.3:1 AFR) at idle. These figures are more like what the main circuit should be producing under load (power).
The adjusted 3.4 % CO (13.2:1 AFR) at idle is still on the rich side. If all your engine management gizmos are working and your air filter is new (clean), fresh plugs and ign timing spot-on you'd get below 1% CO (14.1:1 AFR) at idle easily with no running problems and some fuel saving.
This figure shows relationship between AFR and CO etc ...
This table clarifies AFR and CO% readings ....
If you clean and gap your plugs plus renew your air filter before the next MOT you should have a chance of keeping the CO % below the pass figure.
The adjusted 3.4 % CO (13.2:1 AFR) at idle is still on the rich side. If all your engine management gizmos are working and your air filter is new (clean), fresh plugs and ign timing spot-on you'd get below 1% CO (14.1:1 AFR) at idle easily with no running problems and some fuel saving.
This figure shows relationship between AFR and CO etc ...
This table clarifies AFR and CO% readings ....
If you clean and gap your plugs plus renew your air filter before the next MOT you should have a chance of keeping the CO % below the pass figure.
Peter K
- Tanz
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Re: Emissions data
The air filter is a life time K & N filter. I have a cleaning kit for it so will give it a clean. Plugs are probably due a change anyway. Thanks for the info - could do with a gas analyser at home!!
Cheers, Phil
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- amarshall
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Re: Emissions data
No numbers, again, this year. But is passed again. One advisory on PAS pump possible leak (probably a disturbed hose seal from when the rack was replaced in December).
Not sure how it passed because it's been fouling plugs on 3 cylinders for months and nothing I do to the carbs seems to improve it.
Cold start with choke is usually the worst for it, and results in running on just 2 or 3 at best, but there's a definite build-up over time even without the choke.
Not sure how it passed because it's been fouling plugs on 3 cylinders for months and nothing I do to the carbs seems to improve it.
Cold start with choke is usually the worst for it, and results in running on just 2 or 3 at best, but there's a definite build-up over time even without the choke.
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- marky
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Re: Emissions data
Mine passed at the end of January but I have been busy moving house and struggling with access to this Forum - hence the delay.
CO = 1.32
HC = 100
The carb jets were thoroughly cleaned and carbs re-adjusted during the year.
Mark.
CO = 1.32
HC = 100
The carb jets were thoroughly cleaned and carbs re-adjusted during the year.
Mark.
- Hawaiis0
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Re: Emissions data
Mines just passed . Nothing done to the carbs. Just plenty of use with a 125 mile run to the MOT station
HC - 53.
HC - 53.
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- alanmoss
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Re: Emissions data
Mine has an MOT pass today
CO 1.89%
HC. 154 ppm
One advisory - near side rear wheel bearing has slight play
CO 1.89%
HC. 154 ppm
One advisory - near side rear wheel bearing has slight play
Alan
Excel Celebration, 1999 Mini Cooper S, Dacia Duster 4x4
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- Lotus-e-Clan
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Re: Emissions data
MOT passed yesterday with no advisories this time.
CO 0.35%
HC 115 ppm
I purposely set it lean @ 0.5% CO about 3 years ago (on Iridium plugs) - so 0.35% is in the ball park given differences in measurement accuracy.
All engine management gizmos working, Tesco 100 RON in the tank and it runs sweet atm. Purge pump working so started first time after filling-up.
CO 0.35%
HC 115 ppm
I purposely set it lean @ 0.5% CO about 3 years ago (on Iridium plugs) - so 0.35% is in the ball park given differences in measurement accuracy.
All engine management gizmos working, Tesco 100 RON in the tank and it runs sweet atm. Purge pump working so started first time after filling-up.
Peter K
- MrCoolA
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Re: Emissions data
Mot passed no advisories
CO 1.91%
HC 327 ppm
CO 1.91%
HC 327 ppm
Previously Jerry (Taylor)
Now "Black Flag"
Lotus Excel SEI1989 253.6hp 190lbft
Lotus Elise S3 1.6. Motorsport Green 2011.
Now "Black Flag"
Lotus Excel SEI1989 253.6hp 190lbft
Lotus Elise S3 1.6. Motorsport Green 2011.
Re: Emissions data
MOT passed with no advisories.
CO 1.611%
HC 556 ppm
Checked my emissions with my CO analyser which did read 2.15 so knew it would pass.
Ian.
CO 1.611%
HC 556 ppm
Checked my emissions with my CO analyser which did read 2.15 so knew it would pass.
Ian.
- rbgosling
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Re: Emissions data
First test after the engine rebuild was completed a couple of years ago - the last two MOT testers decided to be nice and "not bother" with the emissions test, which was actually quite frustrating as I wanted to know I did an OK job! Anyway, after about 10,000 miles on the rebuilt engine, my results are:
CO - 1.68%
HC - 758 ppm
I did increase the idle to around 1,200 rpm before the test - I'd be curious to see what it'd get at 800-900, where I normally set it.
CO - 1.68%
HC - 758 ppm
I did increase the idle to around 1,200 rpm before the test - I'd be curious to see what it'd get at 800-900, where I normally set it.
"Farmer" Richard
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)
- mark61
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Re: Emissions data
My car passed it's mot yesterday after being off the road for 9 years. When I got it home I got it running on the fuel that was in it although I did put a few gallons of fresh Asda fuel in it before taking it to the garage and I didn't do anything to the carbs. Car is an Excel LC with 71000 on the clock. I was well chuffed when it passed.
CO: 2.036
HC: 909
CO: 2.036
HC: 909
- rbgosling
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Re: Emissions data
A year later, with 12,000 miles and 3 years since the engine rebuild (didn't do many miles in the last year!), and the scores are:
- CO - 2.44%
- HC - 751ppm
"Farmer" Richard
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)
- Lotus-e-Clan
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Re: Emissions data
CO increase ... if your air filter is new and your ignition timing is advanced correctly I'd check carb balance and if spot-on, slightly lean your idle mixture screws ...
Peter K
- rbgosling
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Re: Emissions data
Timing and idle mixture screws haven't been touched since last year, but then neither has the air filter so it's not the newest. Still, 2,000 miles of driving shouldn't have made the filter too badly clogged.
Without access to an exhaust gas analyser to see what happens, I'm reluctant to start playing around with the idle mixture screws, at least until the emissions become a problem, and there's still plenty of leeway at the moment.
Without access to an exhaust gas analyser to see what happens, I'm reluctant to start playing around with the idle mixture screws, at least until the emissions become a problem, and there's still plenty of leeway at the moment.
"Farmer" Richard
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)
1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)