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[JeremyC]

When i idle the car in the morning it seems to run very rich producing quite unpleasant fumes in comparison to our mx-5.

Could this be a Lambda sensor problem
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'93 Black 33 1.7 16v

[john 33_16v]

Hi,

My catted 33 16v is a tad pungent when it's cold and running on 'choke'. But the lambda is ok and the emissions are usually very low at MOT (lower than my old clio which was 10 years newer).

If the lambda is playing up it will run very rich all the time, generally running rough, and often with flatspots and stammers.

Cheers,


John
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If it aint broke, fiddle with it until it is!
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93 33 16v Mirtle Met
08 Fiat Grande Punto Exotica Red
90 Yamaha FZR600 Genesis- Silky white/red/blue

[BigAl]

Jeremy
I am running my 16v with cat with no lambda correction, as it is knackered, mine also has unburnt fuel smell on idle on cold starts. I know its ok when warm as I recently calibrated mine with no lambda correction connected.
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x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203

[JeremyC]

Thanks chaps, at least I know it's not a sign of a major problem.

I'll have to start parking nose in so I don't fill the house with fumes in the morning.
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'93 Black 33 1.7 16v

[JeremyC]

Al, how do you get your car through an MoT? I thought '93 and later had to have a cat irrespective of emissions?
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'93 Black 33 1.7 16v

[BigAl]

It passed emissions before the lambda died. I'm only running without as it was using too much fuel with lambda connected and my AFM was not calibrated correctly, only found this out when i disconnected the lambda.

Have you tested emissions/CTS/lambda sensor?
You probably already know this but you can clean the lambda by disconnecting the lambda, holding a warm engine at 2k and then adding an air leak until the rpm increases and holding it for about 2 mins, the added heat should clean off the lambda sensor. Thats if its fouled with carbon from rich running. However if it has failed for other reasons like oil silicone you might be better off removing it off and inspecting it. The lambda sensor must be clean on the outside, as it compares the air outside to the air on the inside.

Test the output from your CTS, use the 20k range on the multimeter
Code:

cold hot
2.6ish .28ish New sensor held in header tank
2.6 .23 Old sensor in engine

If your car passes emissions ok then ignore what i have said and i guess live with smell.

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x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203

[john 33_16v]

[BigAl]

Would 2 mins be enough to do that on an engine with no load on it at 2k or slightly above? I would agree if it was done permanently though as it would be running lean all the time and possibly damage pistons??
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x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203