Choke not working

[Verne]

Keif generally starts OK, but runs a little lumpy for the first few minutes and then once warm is fine.

Took the air box connection off the top of the carb to see whether the flap closed when the accelerator was depressed prior to starting. Pic below is after depressing the pedal and as you can see, the flap is wide open. I've done a little research and if I understand correctly, it's vacuum operated. I appear to have a couple of places that possibly should have a hose connected and have done a search, but can't find a image that shows me where all the vacuum pipes should be connected.



There are 2 points arrowed in the pic below that look like there should be a pipe connected. The one lower left looks like it has been cut and the one upper right looks like there is a pipe connection inside. there is also a connection on top of the airbox that has nothing on it.



Can anyone point me in the right direction for a diagram or photo that shows everything. I can't find it in the pdf copy of the Bentley manual I have.

I have read about taking the unit apart and checking the spring etc, but wanted to start with the 'easy' bits first

TIA

[SamsBus2012]

The lower left is your choke vacuum, you should have a pipe from there connecting to a spigot slightly lower and to the left.

The large arrowed pipe on the airbox connector should be connected to the crank breather tower. Ill send some photos

[SamsBus2012]

Sorry about crap photos!
Second shows vac tube from choke pulldown. Assuming yiu have round air filter, you shluld see 2 small tubes on top. These are vac connections, 1 back to carb and 1 goes to air intake. They are used for preheating air. The important one is the one which goes back to carb. It connects to a spigot on the front (cabin side) of carb. This spigot can be blanked off if you dont want to replace this pipe. The spigot immediately next to this one is the vac connection back to the dizzy.
The crankcase breather pipe (large pipe) can bde bought from Heritage or BW for about £30. Some people just use cheap flexi pipe of a suitable diameter. Dont know why pic of this wont upload, sorry

[SamsBus2012]

Slightly better pic



I've been thinking though, if the vac pipe to the choke pull down is missing, that might indicate that bthe pulldown unit itself was leaking. Check to see if the other end of where the pipe should be has been blanked off - sometimes done with a screw into a short length of pipe onto the spigot at the carb base.

You can see the crank breather pipe in this pic - large shiny pipe rising behind the breather tower. Funny shaped thing which loopes back on itself to the opening shown in your original pic.

E D I T: Just looked at your pictures again. You may want to read this thread on the merits of fuel filters in the engine bay:

https://club8090.co.uk/forum/viewtopic.p ... r#p8012200" onclick="window.open(this.href);return false;

[Verne]

Thanks for the response, but I think mine is slightly different to the carb in your pics.

The black unit on mine looks as though it has 2 connections, the one that can be seen in my pic and another directly below it (unfortunately, hidden by the fuel pipe) The lower one loops under the carb to the front as the one in your last pic

[SamsBus2012]

On the shot from above, it is a a pierburg 2e3 which is same as mine. The choke pull down unit on yours does look different. Other pipes same though.

[MidLifeCrisis]

Thanks for the response, but I think mine is slightly different to the carb in your pics.

The black unit on mine looks as though it has 2 connections, the one that can be seen in my pic and another directly below it (unfortunately, hidden by the fuel pipe) The lower one loops under the carb to the front as the one in your last pic

That looks like the 'alternative' choke pull-down unit that some have fitted - it's not the original part (which is very expensive) but a different part that has two vacuum ports - you should find that the other port is actually blocked (I think I can see a small bit of tubing in it in your first pic) - so this is correct - one port of the pull-down is blocked and the other port should have a piece of vacuum hose running from it to a port on the carb (but it shouldn't run underneath the carb as you mentioned - take a closer look and you'll probably see that it actually goes to a port on the carb nearest the back of the van)

Your first pic shows the the choke is not closing when you depress the accelerator pedal at first start up as it should - this is a purely mechanical action so that is probably your problem - there is a spring/coil inside the choke unit (the silver circular bit on the right side of the carb in your first pic with the two coolant hoses going to it) - the action of pressing the accelerator pedal should allow that spring to return the choke to the closed position; you'll need to have a poke around to see what the problem is but that would be where I'd start .... Either the mechanism that causes the throttle lever to release the choke isn't working (or is gummed up with crud) or the spring/coil in the choke may be damaged or misplaced ....

[itchyfeet]

yes same carb but different choke pull down, the pipe as said has a restrictor inside like photo and attaches to the carb below, there is only one stub that's side so obvious where





as also said the air cleaner trunking connects to the oil tower and Brickwerks sell the pipe but currently out of stock, I have seen standard pipe used with a but of stiff pipe inside to stop it kinking on the bends
http://www.brickwerks.co.uk/index.php/b ... bx-dg.html" onclick="window.open(this.href);return false;

if the choke flap moves freely then a common fault is the part below broken, not sure where you can buy them but you could try Bromyard who rebuild these carbs, you have to get deep into the carb to replace it.
https://sites.google.com/site/pierburgc ... rburettors" onclick="window.open(this.href);return false;



finally you should remove that fuel filter from your engine bay, they are not designed to take the heat, there should be just one by the tank underneath.

[Oldiebut goodie]

as also said the air cleaner trunking connects to the oil tower and Brickwerks sell the pipe but currently out of stock, I have seen standard pipe used with a but of stiff pipe inside to stop it kinking on the bends

You can also use piping on the outside to lessen kinking - a lot easier and doesn't constrict the bore!

[Verne]

Thanks guys, that gives me something to go at

finally you should remove that fuel filter from your engine bay, they are not designed to take the heat, there should be just one by the tank underneath.

I fitted that filter last night, as the old one that was there was passed it's best. I do have the one near the tank too, so I'll sort the one in the pic

[ghost123uk]

Note to Verne, remember that breather hose is a vacuum hose with lots of oily fumes in it. This means you cannot use any old bit of hose that fits.

as also said the air cleaner trunking connects to the oil tower and Brickwerks sell the pipe but currently out of stock, I have seen standard pipe used with a but of stiff pipe inside to stop it kinking on the bends

B&Q (etc) sell some black, wire bound, plastic corrugated pipe that works just fine for this and costs next to nowt. I have had some on our van for ages now. You need a bit off the old pipe to act as a joining sleeve at the end, but that is no problem. I still have enough left to make up about 4 breather hoses but as the stuff is so cheap it's barely worth offering, it but it's here if anyone wants some.

[Verne]

Note to Verne, remember that breather hose is a vacuum hose with lots of oily fumes in it. This means you cannot use any old bit of hose that fits.

as also said the air cleaner trunking connects to the oil tower and Brickwerks sell the pipe but currently out of stock, I have seen standard pipe used with a but of stiff pipe inside to stop it kinking on the bends

B&Q (etc) sell some black, wire bound, plastic corrugated pipe that works just fine for this and costs next to nowt. I have had some on our van for ages now. You need a bit off the old pipe to act as a joining sleeve at the end, but that is no problem. I still have enough left to make up about 4 breather hoses but as the stuff is so cheap it's barely worth offering, it but it's here if anyone wants some.

Is this what you mean from B&Q - if so I already have some from when I kept fish

http://www.diy.com/nav/garden/pet-bird- ... Id=9228229" onclick="window.open(this.href);return false;

[SamsBus2012]

Ive seen similar used. Genuine article available from vw heritage £32.

[ghost123uk]

That looks like the stuff I have on mine (for a couple of years now) but I cannot vouch for the size of the stuff in that link being correct. Also B&Q sell it in shorter lengths, so it was much cheaper.

[Eloise]

Hello, can anyone please explain the mechanical process of setting the choke by pressing the accelerator? My choke does not close either and I can see no mechanical means of it closing, I would have expected a cam action on a spring of some sorts.

Thanks