Club 80-90 Forums

my '82 2l Aircooled van's been for a service and sort out today at an Aircooled specialist, the main problem was cutting out at idle and low power.

they did say that it was running really well for them at the garage but had almost run out of fuel they also advised that both carbs need replacing, apparently somebody has bodged a repair with glue.
we went straight to the petrol station across the road and put some fuel in and went on our merry way, yards down the road it started misfiring. we went back to the garage (who were about to close) and they said that it'd be ok when it warmed up. misfiring all the way home, mainly immediately after gear change, got home & left the van for an hour and took it for a spin again and it was still misfiring.

do you think that it would be anything to do with them running the fuel down to almost nothing and cr*p from the tank getting into the carbs?
is it worth trying to clean out the carbs before shelling out on new ones to be fitted?
If i do have to replace both carbs, how much am i looking at??

Hi Karen....

are they standard solex?

if so, I may have a set in the garage....can't remember what state they are in...will need to investigate after easter.


fuel filter may also need a clean - could be muck in that too.

Emma

Thanks emma,

that'd be great if you could have a look after easter.
I'm going to give the guy a call at the garage tomorrow and see if he'll take another look - i appreciate that the carbs are knackered but surely if they were causing the backfiring it would have been happening on the way there.
will check fuel filters & lines over the weekend hopefully (doesn't look as if we'll be going away in the van now )

Good job Nigel's got friday off work, it'll give him another chance to lie under the van swearing at me again!!!!!

Karen,

I am no expert here....but does the following sound like your problem...


from stop....engage first, accelerate away some pull, then distict lack of power, then backfire, then she will go?


Coz that was what mine was doing......turns out that there was a "flat spot" on the carbs. Once through, it pulled fine. Pete did some very fine adjustment of the carbs to overcome this, so when I accerated, the revs increased steadily through the full range.

If on the other hand it is backfiring regularly while driving, that is sommat else?

this is really weird - backfired all the way home from the garage & still backfiring a couple of hours later....

.....did the school run this morning just to test her out (its only 1/2 mile - i usually walk, honest!!) ran perfectly apart from stalling whilst pulling off the drive, but she was cold then. Didn't backfire once

the garage has called this morning to find out if its ok, said to take her for a good run over the weekend and if the problem persists they'll have her back in - they reckon that its probabley some cr*p out of the nearly empty fuel tank.

I just hope its not an on-going problem, i've had the van since november and need to use her!!!!

i bet your chokes are sticking on

I have another quick tip on sorting out misfiring/backfiring twin Solex 34 PDSIT/2 /3 carburettors. I use the hand over the carburettor trick to blast the crap out of the carburettors. This procedure is intended to suck out the sediment from the carburettors.

The first thing you should do is to replace the fuel filter before you do anything else. Check all of the fuel hoses for chaffing, splits and leaks. It is imperative that the fuel hoses are in good condition.

Also check the carburettor blanacing hoses (the ones attached to the left hand carburettor,inlet manifolds and the large pipe at the front of the engine compartment). Replace these if they are suspect.

The hose sizes are the following:-

- Fuel hoses 5mm
- Vacuum hoses: 3.5mm (3.2mm will also fit)
- Inlet manifold hose connections: 9.5mm (8mm will fit after a bit of hot water and soap)
- Top left hand carburettor hose: 11mm ? (10mm will fit after a bit of hot water and soap)

Undo the left hand caburettor heater duct (the rubber hose that goes over the caburettors).

Start up the engine and rev up the engine. Now put your hand over the carburettor throat allowing a very slight leak through your fingers (be careful not to get your hand sucked into the carburettor !!). The engine will sound like a lawnmower at this point. Repeat this procedure a few times until the carburettor has been cleared of sediment, etc.

If the engine still misfires or backfires, switch off the engine and put the left hand carburettor duct back onto the left hand carburettor.

Now undo the right hand carburettor heater duct and start up the engine. Do exactly the same procedure for the right hand carburettor.

Also check the condition of the spark plugs, air filter, rotor arm and distributor cap. Replace them if necessary.

I have no problems with my 2.0 litre Aircooled type 2 T3 (aka "T25"). It does about 25 mpg at about 60 (more than the UK goverment 23 mpg figure). If it's using lots of fuel then there's usually a problem (eg. fuel hoses).

I hope this helps.

Thanks Phade,

Thats definately worth trying at some point. At the moment its running fine, but we havn't took it out for a really long run yet so we'll see what happens when we do.

i think it'd be worth changing the fuel filter as a matter of course and to remember never to let the tank get super empty again.