Club 80-90 Forums

Is it possible to test the secondary throttle diaphragm on a pierburg 2e3 carb without it being fitted to the engine?
I've got a pierburg carb to replace the weber thats on it and would really like to check to make sure it works before i fit it to my caravelle.

yep
take the pipe off the carb and suck air from the unit
it should open the butterfly or work the arm that comes out of it

if you need to continually suck it's shagged
if it doesn't work the arm it's shagged

Cheers.
Just sucked the pipe and the secondary butterfly opened (once i'd figured out i needed to open the first butterfly first ) and it stayed open. Blew down the pipe and it closed.
Just need to make a gasket for the base, fit it and figure out how to tune it properly, then i can fit my LPG mixer ring.

it should close itself... no need to blow, as your carb won't , it only sucks.

Just checked and it does close itself. I was holding the primary throttle open before.
When i release that theres an cam on the arm that closes the secondary as it goes past.

indeed...
infact the more you study this carburettor the less complicated it is

You can fit the mixer to the weber carb by droping the engine crossmember by 25mm and fitting spacers to it. how well it works I won't know until I can get gas and try it (taxing van on monday) I may end up tearing my hair out and trying to refurb my pierburg. watch this space

weimarbus wrote:You can fit the mixer to the weber carb by droping the engine crossmember by 25mm and fitting spacers to it. how well it works I won't know until I can get gas and try it (taxing van on monday) I may end up tearing my hair out and trying to refurb my pierburg. watch this space

if you drop the engine mounting bar by 25mm you will either need to drop the gearbox nose mount by the same, or suffer gear selection issues..... 25mm at the back is about a foot at the stick!! lol!

Mocki wrote:

weimarbus wrote:You can fit the mixer to the weber carb by droping the engine crossmember by 25mm and fitting spacers to it. how well it works I won't know until I can get gas and try it (taxing van on monday) I may end up tearing my hair out and trying to refurb my pierburg. watch this space

if you drop the engine mounting bar by 25mm you will either need to drop the gearbox nose mount by the same, or suffer gear selection issues..... 25mm at the back is about a foot at the stick!! lol!

I have done this part of the modification already and can confirm that there are no selection issues nor any preload on the gear selector to cause wear. not sure if 4 speed box is different mine is 5 speed.

ok, fair play.........
last weekend we unmodified a van that had been crudely dropped 25mm for a webber to be fitted, and putting the engine mounting bar back to its proper position solved all the gear selection issues....its was a lhd 5 speed....
maybe it was a one off.....

Any idea at what revs the secondary throttle opens?

It opens with vacuum not revs
If you floored it at 30 mph in 4th.... it would open.

So if you drive carefully and and use the throttle smoothly and slowly, it hardly opens ...thus saving fuel.

Which is why VW used the 2e3 pierburg as it is such a versatile carburettor

Ahh, clever.