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Aircooled 2.ol only firing on two cylinders
Posted: 16 Mar 2012, 19:54
by 988mick
hi lads im new here and new to vw"s and i just want to say hello and ask for some help with my camper issues.
ive just bought an 83 air cooled 2L and its only firing on nos 1 and 2 cylinders.i bought it like that so iv never heard it running properly.a mechanic had the van and supposedly timed it and cleaned the carbs and cut new gaskets from gasket paper but i think he made a balls of the carbs.
ive got a descent spark on all plugs and i done a quick compression test and got these readings but im not sure i done it right .cylinders 1,3 and 4 are at 115psi and no 2 is at 120 psi.is this an acceptable level or should i go again with the throttle open and try for a different result.the plugs are black with soot on all cylinders and the carbs look iffy.the left carb was closed and the right one was wide open,see pics.i know very little about carbs and am unsure if this is normal any help will be very appreciated.the carbs are solex 32-34pdsit .
cheers.Mick

.left carb

right carb
Re: Aircooled 2.ol only firing on two cylinders
Posted: 17 Mar 2012, 11:03
by Footprint
The compressions are all close together so even if the engine isn't in the first flush of youth it's plenty good enough to run just fine, (should be checked with the throttle wide).
When the engine is cold the choke flaps should be closed as one of yours is, when the engine is hot they should both be open as the other of yours is. So if you took those pics at the same time something is wrong with at least one choke.
That will need fixing before going any further, first check that the spade connector on both choke mechanisms, (the round housing at the top of the carb facing toward you when you look in the rear hatch), is connected and when the ignition is on has 12ish volts to it. If either doesn't it's never going to run right.
Do that first and then come back with your findings and/or fixes.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 17 Mar 2012, 13:49
by faggie
better of dis arming the chokes and removing the 12volt electrical supply to them, you dont need them if the carbs are set up correctly, you dont see auto chokes on webbers or dellortos just 2 pumps of the accelerator before starting and it should be fine i ran a set like this through winter for many years without any problems ,
Re: Aircooled 2.ol only firing on two cylinders
Posted: 17 Mar 2012, 20:21
by 988mick
@footprint thanks for your help and yes the pics of the carbs were taken at the same time.I'll go trough the elec connections again tomorow and do the compression test again and see how I get on.I have a feeling that there is a vacuum pipe on wrong or there is an air leak somewhere but I don't know what goes where myself,il have to see if there is a diagram online of the set up of the carbs and see where the various pipes are supposed to go.I'll dick around with it tomorow and see how I get on.
@faggie
I'll try disconnecting the 12volt to the carbs and see if it makes a difference.
Thanks for your help mate.
Cheers.Mick.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 17 Mar 2012, 20:27
by Oldiebut goodie
I haven't touched a petrol for donkey's years but I would have said that the compression results are good enough to leave as is.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 18 Mar 2012, 10:48
by faggie
if you disconnect the 12 volt supply it wont make any difference, in fact it will make it even worse , you need to disarm them, to disarm undue the 3 screws on the choke unit and turn the whole unit clockwise untill the flap is in the wide open position remove the 12 volt connection from the choke unit and tape up the 12volt supply, or bettter still rewire from the coil + connection minus the 2 connections to the choke units
Re: Aircooled 2.ol only firing on two cylinders
Posted: 19 Mar 2012, 12:38
by 988mick
I checked all the elec connections on the carbs and they are all getting power.
I've re checked the compression twice with the trottle open and got the same readings both times,these wer
(No 1 120psi) (No 2 140psi) (No 3 130psi) (No 4 140psi).
Ive also realised it's using an electronic dizzy not points,is this a good thing or a bad thing.
Next stop vw garage I think.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 19 Mar 2012, 12:49
by jason k
get it to someone who knows what they are doing. most garages are not up to speed with these motors.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 19 Mar 2012, 13:12
by 988mick
I here you mate,I think thats what the prob is I think someone was at it that didn't know what they wer doing.it's going to a garage that specialise in classic vw camper restorations and repairs.I'll get it sorted by the professionals and I'll maintain it meself afterwards,
Re: Aircooled 2.ol only firing on two cylinders
Posted: 22 Apr 2012, 18:34
by 988mick
hi chaps.
i left the van into a vw camper specialist who recommended i just replace the engine as it has 140000mls on her its not worth reconditioning the heads and barrells as it would cost too much and i should just buy a second hand or recon engine.i still wasnt convinced that it was that serious and was sure it was a carb problem. i personally think he doesnt know his a*** from his elbow and just didnt want to do the fault finding.i bought a complete second hand engine ready to bolt in and fitted her and she is running fine now.the other engine was grating on me mind so the other day i whiped the carbs of the running engine and bolted them to the supposedly knackered engine and it ran perfect on all four cylinders.
i cant wait to drive down to the gobshite and show him how well the van is running now.
Re: Aircooled 2.ol only firing on two cylinders
Posted: 22 Apr 2012, 18:42
by fullsunian
I would say the problem is all down to carb setup....as everyone has said before, the chokes are wrong for a start. As you say its only running on one side of the engine so the problem is the other side....I would strip that side carb down and make sure that the needle valve is not stuck closed (have seen this before). If its not they (the carbs) need balancing/setting up and im sure that will sort your problem..
IAN