19 replies to this topic

[TheDurstOfTimes]

Hi,

 

I have a 1992 Cooper 1.3 spi. I am trying to get it through the MOT, it's passed on everything except emissions, which are far too high.

 

CO 1.12% idle

CO 0.94% accelerated

Lambda 1.05

 

The car starts and runs fine. No stalling, no hunting or rough running or fumes smells or anything like that. I've tried loads of things, read many posts here on the forum, and I just can't get the emissions down.

Things I've already changed:

new Catalytic converter

new Lambda sensor

Air filter

Spark plugs

Manifold gasket

Exhaust gaskets

Coolant temp sensor

ECU vaccuum pipes have no cracks or leaks

 

I've also tried fuel additive to bring the CO down, no luck. I'm now totally stuck and don't know what to try. Could an exhaust leak make the CO so high? Can I dismantle and clean the SPI to make a difference? Please help!

 

[r3k1355]

Is there no idle CO adjustment?

[jamesquintin]

"ECU vaccuum pipes have no cracks or leaks"

 

Have you actually replaced them? I've read that they are a service item, so you should try changing them

​Q
 

[FlyingScot]

"ECU vaccuum pipes have no cracks or leaks"
 
Have you actually replaced them? I've read that they are a service item, so you should try changing them

​Q

They are indeed service items. Bin the lot and replace them including the fuel trap - this is what I recommend first before spending big money on new sensors. If they have cracks or splits you probably won't see them in my experience anyway.
Check for leaks at the exhaust manifold in case you are drawing in air prior to the lambda sensor.

BUT BEFORE any of this make sure that the basics are right, clean air filter, oil, spark plugs, fuel filter and tappets set correctly (it's still a mini).

FS

[TheDurstOfTimes]

 

"ECU vaccuum pipes have no cracks or leaks"
 
Have you actually replaced them? I've read that they are a service item, so you should try changing them

​Q

They are indeed service items. Bin the lot and replace them including the fuel trap - this is what I recommend first before spending big money on new sensors. If they have cracks or splits you probably won't see them in my experience anyway.
Check for leaks at the exhaust manifold in case you are drawing in air prior to the lambda sensor.

BUT BEFORE any of this make sure that the basics are right, clean air filter, oil, spark plugs, fuel filter and tappets set correctly (it's still a mini).

FS

 

Okay, I'll try replacing all the pipes and the trap. If there is a leak where the manifold joins to the downpipe (where the lambda sits), would that cause CO to be high? Would it not just affect the Lambda?

[minimans]

The Lambda sensor is what controls fueling, If you have an air leak drawn into the exhaust before the sensor it will see too much oxygen and richen the mixture causing the CO to rise

[TheDurstOfTimes]

The Lambda sensor is what controls fueling, If you have an air leak drawn into the exhaust before the sensor it will see too much oxygen and richen the mixture causing the CO to rise

There's an exhaust leak where the manifold joins to the downpipe bit, exactly where the Lambda fits into. I can put my hand up there when it's running and feel it blowing out. Would that make high CO?

[r3k1355]

More than likely.

[Sprocket]

High lambda with relatively high CO?........... what about HC? High lambda suggests there is an excess of oxygen in the exhaust gas, while the high CO suggests there is a lack of oxygen in the exhaust gas, the two results contradict one another. 

 

You may have an air leak somewhere on the exhaust. It may be a leak before the lambda sensor making the actual burn rich, while still showing an excess of oxygen, or, it might be a leak after the lambda sensor showing as excess oxygen, but the engine is just running rich because it has a fault, more often than not a faulty lambda sensor combined with poor 'tune' (someone previously trying to bodge it and fix it).

 

I would first look at the diagnostic to see what the Lambda sensor is actually doing at idle before anything else. Maybe chase down any exhaust leaks front to back on the car.

[minimat]

Mine is a 1994 spi and dosent requre a cat test, worth checking if yours does or not as its two years older.

https://www.gov.uk/g...3-4-5-and-7.pdf

Page 167

Edited by minimat, 17 June 2017 - 08:58 PM.

[r3k1355]

Yep there is exemption for cars upto 31st July 1995 IF there is no exact match in the MOT database for the car.

Most testers don't bother and put it down as a fail just on the BET test.

 

Double check they are taking the time to find and exact match as the MOT manual says.

[TheDurstOfTimes]

Yep there is exemption for cars upto 31st July 1995 IF there is no exact match in the MOT database for the car.

Most testers don't bother and put it down as a fail just on the BET test.

 

Double check they are taking the time to find and exact match as the MOT manual says.

I'm in Spain, if that makes a difference. The car papers say catalytic converter, so they have to do it that way. I think.

[minimat]

Might have been handy to mention that minor detail at the begining as it unlikely anyone here will know what the spanish rules are regarding their version ot the mot or whatever they call it!

Maybe you could tell us the regulations so people can try and help you more.

[Sprocket]

Might have been handy to mention that minor detail at the begining as it unlikely anyone here will know what the spanish rules are regarding their version ot the mot or whatever they call it!

Maybe you could tell us the regulations so people can try and help you more.

 

 

It says "Alicante" in his user profile as location. I thought that would have been enough?........................

[r3k1355]

 

Might have been handy to mention that minor detail at the begining as it unlikely anyone here will know what the spanish rules are regarding their version ot the mot or whatever they call it!

Maybe you could tell us the regulations so people can try and help you more.

 

 

It says "Alicante" in his user profile as location. I thought that would have been enough?........................

 

 

Yea but it also says he's trying to pass the MOT, which is a British test that most people on here are familiar with so you can understand why everyone assumed they were in this country.

 

Spain equivalent is the ITV, few people are familiar with it.