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Pierburg auto choke

Posted: 23 Apr 2013, 12:18
by lees
Afternoon all
i am just working my way throw possible causes of my black sooted up plugs, i have removed the air intake from the top, depressed the throttle pedal full and the choke has closed up with about 3mm gap, started the engine from cold after fitting new plugs all good up to now.
I have all fitted a new thermostat as the other took an age to get to temperature, now once up to temp a give it a bit of a rev and the choke comes off fully now this is my query whilst ticking over should the choke close up again till you rev it then open under vacumn?
Mine is fully open when ticking over, is this right?
Cheers for now

Re: Pierburg auto choke

Posted: 23 Apr 2013, 12:30
by kevtherev
the choke should visibly and slowly open, without revving, takes about 6 -8 mins... till it is fully open
When you rev whilst cold the flap should open a bit more as the choke pull down comes into play, then close to it's last position

If it's not opening slowly, I would suggest the mechanism need cleaning and oiling

Re: Pierburg auto choke

Posted: 23 Apr 2013, 12:35
by lees
Ok will have a look at the choke pull down, my main concern is the choke flap being fully open when warm and not moving when revved? is this not going to control the air intake flow?

Re: Pierburg auto choke

Posted: 23 Apr 2013, 13:15
by lees
Bit of a update, just read through Ben1985 post from the other day, just took the vav pipe from the choke mechanism and sucked like ben s video his choke is moving and mine aint ?
Any ideas?

Re: Pierburg auto choke

Posted: 23 Apr 2013, 14:25
by kevtherev
It's buggered...you need a new one
Brickwerks

Re: Pierburg auto choke

Posted: 23 Apr 2013, 15:40
by lees
I take it that would cause my plugs to black up
cheers Kev thanks for your help :wink:

Re: Pierburg auto choke

Posted: 23 Apr 2013, 16:30
by kevtherev
lees wrote: my main concern is the choke flap being fully open when warm and not moving when revved?

:?

It should be fully open when warm (or after 8 mins) it will not move when revved... because it's fully open

Re: Pierburg auto choke

Posted: 23 Apr 2013, 16:58
by lees
Ok here s where i am up to took the carb off give it a good clean around the choke bits and inside with carb cleaner oiled the choke moving bits, refitted and started again from cold,fired up first time and the choke slowly opened as it warmed up and the high speed idle even worked, once warm gave it a rev and choke opened fully just waiting for the traffic to die down on the M60 and then take it for a run and check the plugs.
My question before Kev was i was not sure wether the choke should be fully open when warm or it only opened when revved to draw more air through,
give you an update date later
Cheers

Re: Pierburg auto choke

Posted: 23 Apr 2013, 17:11
by kevtherev
lees wrote: was not sure wether the choke should be fully open when warm or it only opened when revved to draw more air through,
give you an update date later
Cheers

yes, it should be fully open when warm.


When it's cold it should open when revved past tickover.... to prevent over fueling.
that's what the choke pull down does for a living..
This will only happen while the choke warms up via the carb and choke heaters..and from the coolant temperature rise. All this heat unwinds a bi metal spring that opens the flap.

Re: Pierburg auto choke

Posted: 03 Jul 2013, 05:57
by dandaz
I am using too much fuel but choke is doing it`s job ,the exhaust fumes smell rich is there some sort of screw to regulate this...?

Re: Pierburg auto choke

Posted: 03 Jul 2013, 06:21
by kevtherev
The mixture screw will adjust the amount of air pulled into the carb at idle (air bleed screw)
That's the only adjustment.
This should only be done with a gas analyser
CO should be 2.5%
Increasing the air via the screw will cause the engine revs to rise.

Main jet is set in stone
Main jet comes in around 1500. rpm

Incorrect float height will also cause over fueling

Note.. If you van has passed emissions recently then it won't be running rich.

Re: Pierburg auto choke

Posted: 03 Jul 2013, 19:42
by dandaz
cheers.... :ok

incorrect float height...?

sorry mate I am a bit thick... :D

Re: Pierburg auto choke

Posted: 15 Jul 2013, 13:36
by ozantavsan
Hi ,

I had same problems with auto choke and idle.Then I found the pierburg manual.
I cleaned my carburetor then cleaned again with electrolise.And then a normal cleaning .
I changed middle gasket and bottom gasket.

I controlled auto choke part.I adjusted it with looking from manual.
Now I have no problem.No idle problem ,no auto choke problem.
Before autochoke wasn't working.Now works well.

Pierburg 2E3 Manual (full) : https://hotfile.com/dl/232365941/49190c ... e.pdf.html" onclick="window.open(this.href);return false;

Carburetor cleaning at home : http://ozantavsan.blogspot.com/p/sende-yap.html" onclick="window.open(this.href);return false;