1600 ct engine failed on emissions

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2011dandd
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1600 ct engine failed on emissions

Post by 2011dandd »

Hi folks

My my camper recently failed it’s mot, one point it failed on was the emmisions. How can I improve the emissions? Any advice much appreciated. Cheers

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937carrera
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Re: 1600 ct engine failed on emissions

Post by 937carrera »

You may get better advice if you say what the emissions were (all the readings, not just what it failed on)

When was the van last serviced ?

How much running has it had recently ?
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Hi thanks yes that all make sense.

Van has not been run much since September last year. Although i put some fresh fuel in and let it idle for ten mins before setting off on the 20 mile journey to the mot test centre, which I would have thought would allow it to get plenty hot enough to burn cleanly.

I service it once a year at least and only complete about 2000 miles a year.
Perhaps I should put the expensive petrol in and a petrol additive for the re-test. I have got new plugs and air filter to put in.

It failed precisely on:

CO: max 3.5% vol actual 6.18 % vol

Cheers

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937carrera
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Re: 1600 ct engine failed on emissions

Post by 937carrera »

It seems as though the carb is simply running too rich.

Right, so here's what I would do:

Remove the plugs and clean or put new ones in - are they black with carbon, put some pictures up.
Air cleaner, replace if the old one is dirty

Then confirm what carb is fitted and how to adjust the mixture.

Make sure the choke isn't stuck on and then weaken the mixture. You will need something to tell you what the CO content is, an old Gunson will do the job (or a new one). If not then just take it to a trusted garage and ask them to adjust the mixture so it shows 2-2.5%.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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sarran1955
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Re: 1600 ct engine failed on emissions

Post by sarran1955 »

Hello,

Odd to find this in 'any other matters'

A video to help with the carb:

https://www.youtube.com/watch?v=Dctz_4dKoJo" onclick="window.open(this.href);return false;

Get a proper gasket kit, and pay particular attention to the small rubber seals on the adjust screws.

Not rocket science...

I am at CO 0.28, no smoke no leaks.

Air-Colled Bliss.. 8)

Cordialement,

:ok
Help and advice on Aircooled engines here:
http://www.youtube.com/user/sarran1955/videos?view=0" onclick="window.open(this.href);return false;

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Cheers guys

I need to check all these things and find out exactly what carb I have and then go from there I guess. I have heard that the carbs fitted to these ct engines are very hard to set up. I do know a guy locally so I will take a look and see what I can do.

Cheers folks.

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Passed the retest
Got my trusted vw mechanic to tune the carb.

But...... now it’s not idling very well and stalling all the time whilst driving, when pulling up and braking at a junction or lights etc.

What do I need to adjust on the carb to sort this?

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937carrera
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Re: 1600 ct engine failed on emissions

Post by 937carrera »

I would take it back to your trusted VW mechanic

You didn't have those problems before, you do now, so probably something he has done.

What were your readings on the MOT test ?
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Don’t know of the top of my head. But considerably lower than the legal limit. He said he would sort it I just want to sort it myself if it’s easy enough. Rebuilt loads of old tractor carbs I just don’t know what screw to go for on these carbs

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937carrera
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Re: 1600 ct engine failed on emissions

Post by 937carrera »

I think it's a Solex 34 Pict 4 on the CT

if it is, here's a workshop manual, in German, but I think you can look at the pictures and work out which is the idle and which is the mixture

https://www.thesamba.com/vw/archives/ma ... _pict4.pdf

Failing that, wait for Sarran
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Thank you.

It was the co screw that was adjusted. Do I dare or shall I just leave it to the professional?

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937carrera
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Re: 1600 ct engine failed on emissions

Post by 937carrera »

2011dandd wrote:Thank you.

It was the co screw that was adjusted. Do I dare or shall I just leave it to the professional?

You said you trusted him, he adjusted it, it isn't right, so the answer seems obvious to me.

Alternatively, make note of where the screw is, count the turns as you adjust it and see if you can get it running better. If so you then have a good running and a "passes MOT" setting
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

2011dandd
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Re: 1600 ct engine failed on emissions

Post by 2011dandd »

Apologies

I am not sure I have been clear.
It failed it’s mot on emissions. The mechanic then adjusted the co screw to what he said was factory setting. It then passed the emissions test but now stalls on idle. So he will adjust it again. I don’t really know what the co screw does so I will read the link and have a think.

Cheers

Pinkythelabrat
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1600 ct engine failed on emissions

Post by Pinkythelabrat »

Not that this is in any way an endorsement of such activities...

But I think the suggestion I have seen is to have a setting which passed an MOT - as it is now.

Then to adjust the screws by a counted number or turns (3 rotations left for example) to a ‘it runs best here’ setting.

And to run with the ‘runs well’ setting until MOT time when you revert to ‘passes the MOT’ setting.

Not endorsing this at all...


Sent from my iPhone using Tapatalk

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bigherb
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Re: 1600 ct engine failed on emissions

Post by bigherb »

2011dandd wrote:Apologies

I am not sure I have been clear.
It failed it’s mot on emissions. The mechanic then adjusted the co screw to what he said was factory setting. It then passed the emissions test but now stalls on idle. So he will adjust it again. I don’t really know what the co screw does so I will read the link and have a think.

Cheers
Simple carbs had trouble meeting the emissions standards and had to run very weak mixtures, one of the problems running weak mixtures is poor idle and stalling coming off the throttle, extra gubbins had to be fitted to overcome the problems, in this case, a throttle damper was fitted to hold the throttle open just before idle and then slowly close it, Check yours is working first.
You can increase the mixture to help overcome the problem, turn the mixture screw anticlockwise half a turn at a time to increase the fuel mixture.
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