Hiya all,
Ive just got my 1980 2000cc Aircooled through the MOT and am on the road at last.
When it 1st failed the MOT the co2 emissions where 7.5%. A mechanic friend of mine adjusted the mixture (without guages etc) and when i went for the 2nd MOT it was about 1.5%.
Im not sure if this is related but last night on my 1st bit of proper driving for 3 months it would dive along at 55-60 for a while then suddenly lose power for a bit then pick up again.
Do you thin the mixture is too weak or could somthing else be wrong?
Thanks in advance
Neal
Losing Power
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Horney
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As you have stated the mixture was fiddled with to get through the MOT then I would suggest your first port of call is getting the timing and fuelling set up correctly. Hopefully that should sort it.
Nick
Nick
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Horney
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Best to double check I would have thought, especially if you are able to do it yourself.
I'm no expert on these engines but I have spent many years playing with minis and MKII Golfs and the starting point of any rough running is timing, fuel/air and then start looking at the leads, dizzy, vacuum pipes etc.
Nick
I'm no expert on these engines but I have spent many years playing with minis and MKII Golfs and the starting point of any rough running is timing, fuel/air and then start looking at the leads, dizzy, vacuum pipes etc.
Nick
[IMG:699:99]http://i4.photobucket.com/albums/y115/H ... nature.jpg[/img]
Horney wrote: the starting point of any rough running is timing, fuel/air and then start looking at the leads, dizzy, vacuum pipes etc.
Nick
Ive just got hold of a strobe light to do the timing but im damned if i can find the timing mark on the flywheel pully !!!
Spend 2 hours slowly turning it, looking and feeling but nothing !!
Surely there must be one !!
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CovKid
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If the timing wasn't changed I'd leave well alone. Every Aircooled I've ever owned has been 4.5% on emissions. Unlikely you'll get it below that and still run reliably. Try increasing the mixture a little.
E D I T:
I used to tune Aircooled vehicles on a regular basis (I was a Bug mechanic in a former life) and after getting them set up correctly the emission figure was always around that figure as a matter of course. The 2litre version (and lets face it, its just a big Beetle engine at heart) will be about the same. The most common problems I had to deal with were where the owner had tried to adjust BOTH timing and carb and got so far away from where they should be, I'd have to start from scratch. If your mate only adjusted the mixture then stay with that otherwise you'll be tinkering all day.
As a matter of interest, on a BUG you basically run the engine around 2000 revs by adjusting the idle screw (fast idle), screw the mixture screw in until the revs just start to drop than back out by half a turn. Set timing, recheck carb, reduce idling speed, recheck timing again and that should be it. And it'll be 4.5%. Other things that notoriously cause rough idling or dying at junctions is a worn throttle flap hinge (ie the rod to which the flap is attached that goes through two bushes in the carb body. Any ingress of air here (and worn bushes will do it) cause an erratic idle to say the least. Theres a guy in Clacton - Roger Ball - Totlands Drive (in the phone book) who can rebush most VW carbs with phosphor bronze bushes. He does an excellent job at very reasonable cost and one heck of a lot cheaper than a brand new carb - just a tip.
To set carb: Make sure the autochoke is fully off and engine warm. Just set the idling speed up a little, unscrew the mixture screw so its running steady, then gradually screw it in until you just hear the revs drop. At that point unscrew it half a turn. Then reset idling. Job done.
Timing: Sadly yes there WERE a few around with no damned mark on the pulley. There are also a variety of them with DIFFERENT marks - even more annoying. Invest in a custom degreed one or at least one with a known mark on it. Otherwise its down to determining where Top Dead Centre (TDC) is. The only things that really upset the timing are wear on the heel of the points (if you have points). Oddly enough the buff cardboard from underneath the last paper in a Rizla packet is VERY close to the gap needed for points if you ever get stuck for feeler guages while you're out (Not Swan papers - that ones too thin)
E D I T:
I used to tune Aircooled vehicles on a regular basis (I was a Bug mechanic in a former life) and after getting them set up correctly the emission figure was always around that figure as a matter of course. The 2litre version (and lets face it, its just a big Beetle engine at heart) will be about the same. The most common problems I had to deal with were where the owner had tried to adjust BOTH timing and carb and got so far away from where they should be, I'd have to start from scratch. If your mate only adjusted the mixture then stay with that otherwise you'll be tinkering all day.
As a matter of interest, on a BUG you basically run the engine around 2000 revs by adjusting the idle screw (fast idle), screw the mixture screw in until the revs just start to drop than back out by half a turn. Set timing, recheck carb, reduce idling speed, recheck timing again and that should be it. And it'll be 4.5%. Other things that notoriously cause rough idling or dying at junctions is a worn throttle flap hinge (ie the rod to which the flap is attached that goes through two bushes in the carb body. Any ingress of air here (and worn bushes will do it) cause an erratic idle to say the least. Theres a guy in Clacton - Roger Ball - Totlands Drive (in the phone book) who can rebush most VW carbs with phosphor bronze bushes. He does an excellent job at very reasonable cost and one heck of a lot cheaper than a brand new carb - just a tip.
To set carb: Make sure the autochoke is fully off and engine warm. Just set the idling speed up a little, unscrew the mixture screw so its running steady, then gradually screw it in until you just hear the revs drop. At that point unscrew it half a turn. Then reset idling. Job done.
Timing: Sadly yes there WERE a few around with no damned mark on the pulley. There are also a variety of them with DIFFERENT marks - even more annoying. Invest in a custom degreed one or at least one with a known mark on it. Otherwise its down to determining where Top Dead Centre (TDC) is. The only things that really upset the timing are wear on the heel of the points (if you have points). Oddly enough the buff cardboard from underneath the last paper in a Rizla packet is VERY close to the gap needed for points if you ever get stuck for feeler guages while you're out (Not Swan papers - that ones too thin)