Idle problems

[Nicola&Tony]

Kev the Rev is a star.......

The boy done good (again)!

Tony

[Novice in need]

The Choke pull down unit has been ordered (arrival Tues) turns out that Brickwerks are doing a modified version from another vehice as Kev rightly said the T25 unit is obsolete!!!

When cleaning the carb i have read about dismantling it and to be honest that sounds far to ccomplicated for a novice like myself to attempt, so i am considering using a spray cannister cleaner to clean it up rather than a complete rebuild?
Would this be ok? or should i just go for it and do the rebuild and get a carb kit etc?

[kevtherev]

there's really not much you can break when cleaning the float bowl and jets.

The carb has two half's, once separated the bottom half can be cleaned out and the two jets cleaned with a nylon bristle (NOT WIRE !!)
The top half using the bristle again in the air bleed jets (TOP)

if the gasket is shagged renew it.
Then look at the fast idle mechanism (side) for any spring stretching or broken.
There's another "black thing" on the back of the carb, this is the second stage throttle operated by vacuum, again check it's action by pulling off the pipe from the carb body and sucking, you should see the butterfly valve in the throat open.. and stay open if you put your tongue over the pipe to seal the vacuum, if the butterfly valve shuts that unit is letting air into the engine too.

when it's back together and filled with petrol you can check the transfer jet, this jet helps you accelerate smoothly by chucking a bucket of fuel straight into the main venturi.
it operation is checked by getting a friend to press the accelerator and while looking straight down the throat, you'll see a good squirt of fuel spray into it

[Novice in need]

Thanks Kev

So i dont have to completely dismantle the carb to change the Choke pull down unit? sorry but Im trying to get a decent diagram possibly a step by step guide on removal of the Pierburg 2E (i have been reading up ) but cant find one with enough detail, Bentley download manual doesnt appear to cover the carburettor, will invest in a Haynes one i guess unless you know of a better manual?.
"Now if you accelerate or try to, when cold, the flap should open as you depress the accelerator, this is done by the choke pull down unit (the black plastic unit in fig 2)
if it does not the unit has failed and the engine is overchoking" I HAVE ALSO DONE THIS !!! result was that it did not open...


I will attempt the job on Tuesday, thanks onceagain for your help!

[kevtherev]

removal of the carb is a pre requisite really.
once off you will be able to see how the unit is removed ... how it operates... and what it operates..

there'll be a eureka moment and you'll feel pretty smug.

[Novice in need]

Hi all after removing carb with some hesitation and now prior to fully dismantelling the top from the main body iv decided it had better order a gasket whilst i am waiting for the choke pull down unit to arrive...........!!! but here comes another stumbling point where do i get a gasket from???? Brickwerks does only Kits (which dont have a gasket that goes between the manifold and carb..I NEED ONE OF THESE ALSO).

Heritage dont do any as far as i could see on their brochure....Grrr

Could anyong point me in the right direction please?

[kevtherev]

buy the kit
that old carb has been dealing with petrol for over twenty years, you certainly won't do any harm fitting some of it.

you can re use the old manifold gasket as it's very thick, remove it carefully and clean it up, I don't use a gasket sealer on this or any other carb gasket. But that's up to you.

[Novice in need]

Hi Kev i am happy to buy the kit however the kit doesnt contain the manifold gasket and there was NOT one on when i took the carb off it was fixed down by some sort of sealant O iv just seen some guy make his own on Utube....is that an option ?

[kevtherev]

yes it most certainly is .. the original gasket was about 5mm thick.

[Novice in need]

Thanks i think i may have to go down that route... unfortunatelly the top wont seperate from the body as it appears whoever has been here before has put a shed load od sealant on and its just not budging!!! ive even tryed a flat screw driver to try and pry it open but its chipping the casing alittle and i dont want to damage it.
wondering what madness came over me when i decided to buy a bus........... any way i may have to go the whole hog and get a full replacement if i cannot get it apart so that i can complete the repairs.

Thank you once again

[kevtherev]

you have to remove the carb and screws to separate the halves



click the picture to zoom in

[Novice in need]

Hi Kev

Thanks for diagram, i have however removed from vehicle and taken the 4 bolts out from the top diagram only shows 3, = 28 29 and 24 but the top still wont lift off hence why i believe it is the sealant holding it on.

Il go back over it but im certain there is no more bolts that could be holding it on.

[kevtherev]

bugger that's a shame ..but it really does need to be separated
if you look at the diagram there are some fairly safe prising points

once you have it started it will fly

[Novice in need]

Hi Kev
Update.... cleaned carb (couldnt however get apart) sprayed carb cleaner down throat and basically turned upside down to get bits out, seemed to get alot out, also dismanteled coil housing where there was crap partially stopping the spring from closing properly.

Replaced Choke pull down unit and checked the other black unit at the back of carb this was ok vacum working, also petrol feed valve was chucking out a good amount of petrol aswell all hoses appeared ok with no visible signs of perishing etc.
Put it back on and it fired up ok sounded alot better in respects of running at a more acceptble idle speed than before. (it would appear the previous owner had been adjusting the choke coil to compensate the broken pull down unit casing was broken so visibly aswell as lack of vacum functionality was evident) i have re set at what i believe is the factory setting ie on the markings on the coil housing.
This all however needsto be set properly!! im awaiting a Haynes carb manual as i write

Just one major worry thou oil spitting out of exhaust (rebuild?) however goes once engine heats up...
Guess il be a club 80-90 regular lol

[kevtherev]

sorry mate your going to need a gas anyliser to set that mixture correctly I can imagine it's running extremely rich at the moment if an air leak has been compensated for.
The most important settings you need to pay attention to are the choke flap position and action during cold and warm up procedure, 2nd action under full load, and idle speed cold start setting.
Your local mot station should be able to adjust the mixture, Pierburg 2e3's were fitted to quite a lot of vehicles.

At some point you might do well to look for a cheap pierburg 2e3, Billy Bodger has well and truly buggered that baby up.
they are not that expensive 2nd hand at VW shows and such.

here's some info on re setting your cold start idle cam stepper

Fast idle cam (from cold) adjustment
For adjustments to this part of the carb it must be removed, along with the bi metal spring and housing.

1/. Adjustment of fast idle cam must be done using a vacuum pump mechanism to the 2nd stage choke and create a vacuum around 300 Millibar
2/. Open the throttle , to freely move the cam.
3/. Gently move the lever (c) or the dog in the bi metal spring housing, clockwise and then release the throttle valve.
4/. Check the distance (x). It should be 0.2 - 0.8 mm.
Adjust the value using distance lever (d)



With carburettor off "set" choke as normal (manually) the throttle stop screw A should sit on top of cam lobe 1, once the throttle shaft is moved it should drop to cam lobe 2.... then when the carb is on the engine the coolant temp will move it down the cam progressively .

Further refinement can be found using screw A when engine is HOT and at working temp adjust screw A to final cam lobe 4 to just touch the surface of lobe.