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Model specific boards => Golf mk2 => Topic started by: bmouthboyo on 15 April 2011, 11:32

Title: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: bmouthboyo on 15 April 2011, 11:32
Hi guys,

I bought a gas tester to set the fuel / air ratio on my kjet engine.

Can anyone advise what % I need to set it to given the engine and vehicle for an MOT?

Does the limit depend on vehicle or engine?

Obviously due the engine being at rear of the vehicle it does not have a cat converter fitted. Will I have to adjust the Co2 to take this into account?

Cheers
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: danny_p on 15 April 2011, 12:42
1.8%  iirc
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: SoundillusioN on 15 April 2011, 13:04
1.8%  iirc

correct and don't fret too much about it as the the emissions if tested are on the year of the engine, not the car.  A mk1 DX would never have had a cat.  I think the limit is much higher than 1.8% to pass.
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: danny_p on 15 April 2011, 13:11
anything under 3.5% is good for a pass.   

TBH its a massive goal to aim for,  when i'm serviceing and getting things ready for mot  i don't normaly bother useing a gas tester anymore. you get the feel for them and there a pice of piss to setup by feel if there going to setup.  and emission test from mot usally comes back saying there spot on.  gas tester only comes out when there being awkward   

Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: bmouthboyo on 15 April 2011, 14:23
thanks guys, i got it to 2.0% so that should be fine.

After MOT is there and ideal setting? or is that the sweet spot anyway?
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: Wayne on 15 April 2011, 14:49
thanks guys, i got it to 2.0% so that should be fine.

After MOT is there and ideal setting? or is that the sweet spot anyway?

Sounds fine  :smiley:

Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: bmouthboyo on 21 April 2011, 11:46
OK so today it passed it's Emissions but the readings seem very low:

CO Level - 0.12%
HC Level - 598 ppm

Now at home using my Gunson Gas Tester I set it to 2%??

Also after getting the vehicle back it fails to idle well and I had a pig of a job starting it when I stopped at shops on way home. Is it usual for garages to fiddle with the idle or fuel / air ratio during MOT? My van doesn't have tachometer so the idle speed section is blank on the results.
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: Wayne on 21 April 2011, 12:28
OK so today it passed it's Emissions but the readings seem very low:

CO Level - 0.12%
HC Level - 598 ppm

Now at home using my Gunson Gas Tester I set it to 2%??

Also after getting the vehicle back it fails to idle well and I had a pig of a job starting it when I stopped at shops on way home. Is it usual for garages to fiddle with the idle or fuel / air ratio during MOT? My van doesn't have tachometer so the idle speed section is blank on the results.

That is very low co level, might be the fuel pressure dropping which is making it hard to start.
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: bmouthboyo on 21 April 2011, 13:16
What could be causing the fuel pressure to drop? Weird thing is it was fine before the MOT, although admittedly to the station was the first time I have driven it. And I only just set it to 2% using my Gunson gas tester the other week.

It has had new filter and tank flushed when I serviced it.

Bit stumped really as I can't test the pressure cause CIS fuel pressure testing kits for the Kjet system are like hens teeth.

Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: Neo Badness on 21 April 2011, 14:37
OK so today it passed it's Emissions but the readings seem very low:

CO Level - 0.12%
HC Level - 598 ppm

Now at home using my Gunson Gas Tester I set it to 2%??

Also after getting the vehicle back it fails to idle well and I had a pig of a job starting it when I stopped at shops on way home. Is it usual for garages to fiddle with the idle or fuel / air ratio during MOT? My van doesn't have tachometer so the idle speed section is blank on the results.

I don't wish to thread crash but I had a similar experience with the 16v KR would need to double check the emission part of mot but wasn't far off that.
Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: bmouthboyo on 21 April 2011, 20:07
I have just been out and reset it to what I think is 2% but I had to adjust it blind earlier after it wouldn't start post MOT.

To be honest turning the adjustment screw doesn't make a drastic difference, and going by others saying small turns clockwise will increase richness it is no where near that sensitive. I managed to get it up to 3% and was running well, but revving it gave a little bit of smoke so put it to just over 2%.

However when I took the tester out and let sit in air it settled on 2.5% so according to manual means it may have been 0.6 less than I thought. Not exactly an art.

Also the RPM screw is at low as it will go, and as i don't have rev meter had to kinda do it by ear which was lowest setting.

I still have no idea why the MOT said it was 0.12%? That must be near impossible on a 24 year old K jet engine stuck in a van!

I am not using my Gastester wrong am I and should be going 2% above the initial calibrating 2% from air?

Title: Re: Mk1 DX Engine in T25 Camper - Co2 level?
Post by: mwep201081 on 21 April 2011, 20:49
I have just been out and reset it to what I think is 2% but I had to adjust it blind earlier after it wouldn't start post MOT.

To be honest turning the adjustment screw doesn't make a drastic difference, and going by others saying small turns clockwise will increase richness it is no where near that sensitive. I managed to get it up to 3% and was running well, but revving it gave a little bit of smoke so put it to just over 2%.

However when I took the tester out and let sit in air it settled on 2.5% so according to manual means it may have been 0.6 less than I thought. Not exactly an art.

Also the RPM screw is at low as it will go, and as i don't have rev meter had to kinda do it by ear which was lowest setting.

I still have no idea why the MOT said it was 0.12%? That must be near impossible on a 24 year old K jet engine stuck in a van!

I am not using my Gastester wrong am I and should be going 2% above the initial calibrating 2% from air?



take it somewhere proper and get it set up by someone who knows what they are doing. tune up usually costs me 25-35 quid, which you'll save in fuel, especially in a bus, in no time!!