Ignition amp testing

[Elsaetka]

Oh dear now your asking. To be honest (and I am slightly embarrased by this as I used to work for VW), I didnt get the emissions report handed over when I picked it up, it's probably still attached to the job card, but a pass is a pass so I forgot about it at the time.

It was MOTd by a VW main dealer, they had to put Fortron in it to get it through. I'm paranoid it runs into trouble this time around but saying that, it's had a lot more use this year, plus its getting an oil and plug change right before the test (9th January).

Saying nowt, but any emission reducing tips would be welcome, never had a problem before.

[itchyfeet]

co is measured at idle and can be adjusted with a screw on the carb
hc is usually a sign of a worn engine burning oil but fresh engine oil can help also a thicker oil if it's burning it.

[Elsaetka]

Will have to make sure I ask for the printout this time and post the results on here.

I tackled problem from both sides, oil was too thin at the time, (i'm sure it was Magnatec), ive the proper grade in there now, mind you it doesnt use much at all, rarely needs a top up.

Plus as I say it had been laid up for a long time which wouldnt have helped, used much more in last few months. Changing the air filter and plugs before MOT.

[ajsimmo]

High HC can also (often) be a sign of an air leak leaning off one or more cylinder(s), causing incomplete combustion or a misfire, leaving raised levels of unburnt fuel in the exhaust. If richening the mixture reduces HC then it points to this. If not, but removing the breather pipe lowers HC dramatically, it's more likely bore wear and oil consumption.

[California Dreamin]

You are doing all the right things: clean oil (15W40) plugs & an air filter. Assuming that you are going to a 'while you wait' MOT or that it will be tested soon after dropping off? then getting the engine up to temperature (a good 20 minute drive, sustained speed is best) is going to help you the most.

Part of the MOT stipulates that the engine oil must be at least 80C before testing the emissions, this occurs some time after the coolant has reached is 'running temp' because it relies on 'Load' rather than just running at idle (the engine needs to be worked).

Of course these things just 'help' and cannot compensate for incorrect throttle butterfly/mixture/idle by-pass adjustments.... or general engine wear.
It is quite common to find that someone has adjusted the idle speed using the throttle stop instead of correctly using the idle by-pass screw. Even more common to find the combination of mixture and idle by-pass screw have been incorrectly adjusted.

Martin

[itchyfeet]

Haynes Piergurg 2e3 carb manual lists the throttle stop screw as idle speed adjustment.
No idle bypass screw listed for the 2e3, just an idle mixture control screw which is used to set idle co.
question from Elsaetka makes no mention of LPG

[syncroandy]

Just seen this due to the bump...

If anyone else happens here, seeking the information in the OP, the checking procedure for the TCI-H switch unit (aka. N41, ignition amp.) is on page 28-26 of this workshop manual:

Workshop Manual Volkswagen Transporter 1980> Digijet, Digifant Fuel Injection and Ignition System

[ajsimmo]

Of course these things just 'help' and cannot compensate for incorrect throttle butterfly/mixture/idle by-pass adjustments.... or general engine wear.
It is quite common to find that someone has adjusted the idle speed using the throttle stop instead of correctly using the idle by-pass screw. Even more common to find the combination of mixture and idle by-pass screw have been incorrectly adjusted.

Martin

Old post, but I had to smile at re-reading this, as I've noticed Martin defaults to fuel injection mode in almost all his replies! It's a DG, Martin, and therefore a carb (probably, unless it was a cheap fix for a poorly DJ/MV etc van).
Did this HC problem get resolved?