Emissions - MOT

Booked my 1980 series 3 2.25 petrol in for it's MOT for monday- been off the road for a couple of years with the previous owner.

Had a big list which it failed on last time which I've worked through, however, the one I'm a bit unsure what i can do before it goes in, is the emissions.

Have changed sparks, cleaned air filter and turned some screw on carboretter so it just ticks over (however think it's not the original carb as there's a bit of a tight fit with the accelerator arm connection and can't turn screw all the way) anyway after all the aboove are there any other suggestions to help it through?

cheers.

Put in new fuel if u havent already it goes off after a while, and take it a good blast like down the motorway to clear everything out. It shuld help.

yeh take it for a good run somewhere fast (within the law obviously) this clears all manky substances out of exhaust and flowing system
yes i agree new fuel is good and clean your air filter fresh oil in air filter

Sounds a bit "Due South", but I often sniff the exhaust to see if I can smell unburnt fuel. You could use a colour tune to check for complete combustion. I tend to adjust the fuel richer till the revs drop, then leaner until they drop again. I then put a vacume guage on the car, tweak the timing. To get the best steady vacume I can, minus 1/2 inch mercury. Then richen the fuel a bit, and lean it up again... This means you are burning everything that is going in, as when the revs drop it's cos the burning fuel has. Check yer points too, before you start.

You have to be careful just screwing the idle jet in, some carbs have a pin going toward a neoprene pad inside the carb. Screwing the pin in too far can a) damage the pad b) knacker the pin.

If you have done all of the above, and it still fails you would be hard pressed to prevent it. Probably means yer jets are worn out. I always make sure the car is warm before the MOT is done, a cold engine is more likely to have higher emissions. I have gone to a garage before now and just asked them to check the emissions, I seem to remember they did it for free...

Go on, live man! Landie are an adrenalin sport, live life on the edge.... Who said the servicing was any different?!?

Contrary to many stories, a well maintained SIII 2.25 Petrol is not a particularly high emission engine... It does very well even compared to non-ECU saloon cars, well within the emissions specs.

Mind and keep yer tickover down about 800ish, less bangs, less fumes...

The old series 3's we had in the army used to struggle with the emmisions as they stood at tick over for ages. A quick fix to the problem and to give it a bit of a combustion chamber clean was to run at a high tickover and pour small amounts of brake fluid down the carb choke, whilst pouring give it a good blip until the white smoke clears. They ran a hell of a lot better and a good 3'er would see the other side of 80mph, on the autobahn obviously. Worth ago..

Lee

You get carb cleaner from Halfords that can be used instead of brake fluid, same idea...