17 replies to this topic

[aspicer0]

Hi my mini mpi cooper 1997 failed the MOT on emissions high hydrocarbons and co. I have changed the lambda sensor air temp sensor and the water temp sensor also the cat the leads and plugs also the coil pack the tappets and oil have been done I have checked all the vacuum pipes and still it is failing the ECU have been checked and its ok. the garage is saying its letting in too much air as the petrol is not being burnt.

[steven]

crack in a pipe ?

[aspicer0]

a crack in what pipe all the vacume pipes have been checked

[minidaves]

Stop Stop Stop, fault finding is a logical process dont just change bit and hope one, but problems alloy rocker box caps, servo seals and valve guilds and what are the figures to give us a clue

[Wise Old Elf]

Minidave is correct; high CO and HC just means you are not getting clean combustion. You need to start at the beginning.

The first thing I always check is compression, then spark at all cylinders, ignition timing. If all these are good move onto checking the fuel/combustion using a colortune. Pin it down.

Colortune are great and allow you to pin down a specific cylinder with a problem which can give you a good idea where to start.

J

[Chance]

Im not sure but I know that people with mgfs take them for an Italian tune up before MOTs

I.e a spirited drive for half hour ish before the MOT so it's nice and warm and all the cobwebs are blown out :)

However I dont really know but someone with knowledge might be able to tell me if this is a load of tosh?? :)

[Wise Old Elf]

Im not sure but I know that people with mgfs take them for an Italian tune up before MOTs

I.e a spirited drive for half hour ish before the MOT so it's nice and warm and all the cobwebs are blown out :)

However I dont really know but someone with knowledge might be able to tell me if this is a load of tosh?? :)

The cat needs to be up to operating temp but this does not matter anymore as the current MOT test requires the tester to warm up the engine oil for the gas test anyway.

[Chance]

Thanks for that

Ignore me then

[minidaves]

engine flush new 20 w 50 italian tune up and super unleaed with cataclean :) before i take any cusotmers car in and mine pass, highest mileage 157 never been apart on orginal cat too

[aspicer0]

hi the compressions are fine it had a new head about six months ago from mini speed the tappets are ok new plugs leads and an oil change.
the hydrocarbons are reading 6268 and the co is 3.940.
I have also taken it for a long run before the emissions test each time.
I did change the plug leads around and this sent the hydrocarbons off the scale.
I have been told that the Air Control Valve on Inlet Manifold could be not working. The garage said that it is supposed to close up once the vehicle is warm which lowers the air that enters the manifold I don't think mine dose.

[mk1leg]

hi..and welcome to TMF and enjoy your mini..................

[aspicer0]

Hi I would enjoy my mini if it went
Ive had seven carb models and one SPI and I never had any problems as I have with My MPI
Ive been to my garage five times now and put it on the emisions test soon I will be on their Christmas card list.
The wife wants to sell the Mini

[Guess-Works.com]

the hydrocarbons are reading 6268 and the co is 3.940.

For an Mpi that is way off the scale... as the pass is 200ppm HC and 0.3% CO

in fact for any car that's way off the scale !

[minidaves]

yup thats of the chart, and idicates a massive air leak, head gasket does not do valve guides, the air control valve, yeah take it apart and clean it had a few that have stuck, check anywhere for an air leak thats the only way to get that kinda result.

[aspicer0]

The Head gaskets fine as the comperesions are fine it dont leak water or oil and its had a new head in the last six months from minispeed.
last year it failed on emisions before I owned it they changed the Lambda sensor and the water temp sensor also the cat and had the ecu repaird.
I am going to check out the air control valve as a few people have said that.
do anybody know if it sucks in less air or closes all together when the car reaches operating temp. if so mine dont it just stays the same.