MPI emissions too high
Turbo Mini Forums

my mpi failed the mot on the emissions beig too high, well its the CO that has failed. the fast idle test was 1.213 with a max limit of 0.30 and the second fast idle test was 0.899 again with the limit of 0.30. how can i bring the level down to get it to pass?

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

could it not be a further problem causing the high missions?

doesnt a blown head gasket between cylinders or a burnt valve increase the CO?

i cant remember what mine failed on but it was a burnt valve that caused it

Yes i moved to the darkside

Instagram @jdm_brett

Full engine spec?

Cat fitted?

What are the full emissions test results?

Do you know what the afr is? Could be that the coolant temp or the air temp sensor has failed

Typical things :

1. blocked air filter,
2. blocked breathers, charcoal cannister or rocker cap,
3. coolant sensor fault causing it to overfuel,
4. tappet clearances too tight (sometimes relaxing to In: 0.0014 / Ex: 0.0016 (adjusted when cold) can sort it),
5. engine not up to temperature, faulty thermostat,
6. carbon formation in chambers holding valve away from valve seat or pitted valve seats,
7. faulty air flow sensor
8. fouled plugs
9. leaking head gasket between cylinders

Start with the easy things like filter and tappets then progress to thermostat and a compression and / or leak down test.

Good luck.

Richard.

Edited by turbominivanman on 23rd Nov, 2009.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

its a standard mpi witha cat fitted, the full emissions results are;
fast idle test,
CO max limit 0.300 actual 1.213 fail
HC max limit 200 actual 135 pass
lambda max limit 1.090 actual 1.032 pass
second fast idle test;
CO max limit 0.300 actual 0.899 fail
HC max limit 200 actual 91 pass
lambda max limit 1.090 actual 1.038 pass
natural idle test
CO max limit 0.500 actual 0.289 pass
overall result fail.

going to change the plugs and air filter,and give a good warm up before the next test,was just wondering if the failure values were anything to worry about?

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

Looking at those I'd say its nothing more than a duff lambda sensor.

happy days!, i hope your right tom.

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

Comparing those results to the ones below from a perfectly executed test, it would perhaps be due to an excess of unburnt fuel and oxygen either from a slight misfire, or poor valve seal.

The check list I have attached says its an exhaust leak before the lambda sensor, which would be the manifold to head gasket.

Do all the simple things listed above first though, especialy the valve clearancies


Fast Idle:
co2 : max 0.2 actual 0.042
HC: max 200 actual 19
Lambda: min 0.970,max 1.030 actual 1.007

Natural Idle:
co2 max: 0.300 actual 0.006

Attachments:

78.66kb

That's a bloody usefull diagram Sprocket

I can't do science just bodging