pierburg 2e2 carb idle screw

hi
i have been sorting out my pierburg carb over the last few weeks and i think i am finally there, i have done and check most things it johns pierburg post.
i just have one issue behind the three four point vacuum thing there is a 13mm bolt, this is supposed to be an idle increase/decrease bolt, if i turn mine it does nothing i can wind it in till tight and the only time it changes the idle is when its about to fall out, is this correct, i needed to increase my idle by a few hundred ( it was running about 450-500 and i prefer around 750-800) so i wound in the small stub thread on the front of the unit to get the revs up, is this ok to do as i would assume this is factory set.
Also can anybody tell me what the mixture/c.o settings should be, i wound mine in all the way, then out 3 turns,till it hit the sweet spot but when i wound the screw in i was originally out about 5 turns,which is the correct amount
help appreciated
cheers kurt

Have you looked rubjohnny's guide to the 2e2 pieburg?

link below

http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=61457

hi
yeah i have been using the guide,its been excellent
i have done everything aside from the manifold "O" ring which i shall do when the warmer weather gets here (there is loads of very hot water getting to the auto choke anyway)
Its just there is nothing on there about what the mixture/co setting should be, i usually set the mixture at about 2.5/3 turns as a golden rule but this carb was about 5 turns out and the idle screw on the back of the three four point unit does nothing at all the idle stays the same till it falls out
is this normal on these carbs

need a co meter really, set it to this:
http://vwtech.no-ip.info/downloads/EmissionsSheetEZ.pdf

hi john

yeah i thought i might need to do it that way, i might ask the lads at my MOT place, although to be fair the engine levelled out nicely at around 3 turns out but didnt change much if i wound it out to 5 turns.
The concern i have is with the 13mm idle screw on the back of the 3/4 point unit it does nothing to the idle at all, the only thing that seemed to change is if i screw it in most of the way the first start idle is around 1800 and if i unscrew it half way out the next day its around 2400, this is a real pain to test though as i have to wait till the next morning to check it.
is this screw actually an idle screw or does it set the carbs choke idle
cheers kurt

that isnt really the way you change the idle, that is done by bending the metal lever and/or adjusting the grub screw on the left, the one that touches the 3/4 point unit.

you shouldnt have to fiddle with anything on the carb really it should take care of itself, the only time you may have to is if someone else has fiddled with the settings in the past to work around a problem rather than fixing it.

heres a pdf that goes into a lot more detail on resetting the carb:
http://vwtech.no-ip.info/downloads/haynes2e2manual.pdf

what is the 13mm hex screw for on the back of the 3/4 point unit for :dontknow:
i have wound the c/o mixture screw back out to 5 turns as the car was running slightly lean/weak and have set the grub screw to around 950 rpm idle  
I have also found why my cold start up idle takes ages to return to 950 it seems to be the TTV if i push on the pipe closest to the 3/4 point unit ( the pink one in your diagram) the car idles to around 2500 and will sit like that till i push on the pipe again it will then return to normal idle it will do this regardless if it hot or cold, do these TTV unit go faulty its getting 12v and does click with the ignition

have a read thru the pdf i linked to, it has TTV testing procedures in there. when its idling at 2500, is the 3/4 point unit extended? if so yes thats a problem with the ttv or the vaccum hoses, or maybe even the 3/4 point unit.

once the engine is started it should stay at the idle position whenever the car is idling, if it extends then its lost vacuum.  the pdf dues mention if you  rev the engine it will retract a bit though but i have a feeling that was only on some of them

hi john
yeah i have read the pdf file but i havent had the chance to do the test on there.
It was the pdf that brought my attention to the ttv.This is what happens when i start the car
1. start car,dont touch accelerator
2. car idles slowly from 1000 (slightly choked up 2 seconds) to around 2500
3. sits like that for about 10 minutes then drops to around 750 then slowly picks up to 950.
this whole process is around 12 minutes and can be driven and is lovely when the idle drops to 750
but if i push on the lower ttv pipe were it comes out of the valve itself when the idle first reaches 2500 the whole process is around 3 minutes.
i have a feeling something is wrong with the ttv because if i push on the pipe i can make the vacuum on the 3/4 point unit retract and extend but its only if i push just were it comes out of the ttv unit
push once and the 3/4 point unit extends (2500 idle speed)
push again and it retracts back (950)
but of cause every now and then when i am driving the idle will shot up to 2500 and i have to get out and push the pipe and hey presto back to 950 for another 10 miles or so.
If i pull out the pipe when idleing it will rev to around 2800 and i think 3000 is the norm so its not far out
do you think that the hoses could be faulty and were would i get replacements from
cheers kurt

yeah does sound like ttv unit is faulty or perhaps the pipe from it. maybe the unit itself hasd a split so when you push on it you're closing up the vac leak so it can do its job properly. trouble is mk1/2 in scrappy not easy to find, not like back in 2003 when i was fixing up my mk2

Hopefully its the pipe it does seem odd that when i push the pipe it drops the idle then push again it idles high its like a bloody switch, i shall change the pipes first see if it helps if not search out a TTV

Yeah tell me about it when i first got into mk1's about 12 years ago my local scrappy had loads of golfs cabbys,caddys, tin tops, american imports now they are struggling to get mk2's and some mk3's in, when i think back they had a 76 mk1 for sale or break and all i bought off it was the chrome bumpers and door handles, i paid £20 for the lot  (they only wanted £100 for the car) i went back the next day to get the grill as a spare and they had squashed it 8O , didnt really worry though as i got 2 grills the following week 1 red, 1 chrome there was golfs going in there all the time.
still have the bumpers and door handles on my cabby  
ahh the good old days

thanks for your help so far john

imagine how much money you would get now for that 76 you could have had for 100 lol

tell me about it john, gutted really but didnt know back then.

One thing i wanted to ask is what actually sets the idle during warm up, not the first few seconds when the chokes on, its when the second stage starts and the idle increases to around 2000/2500 i want to decrease that to around 1500/1750 but i can figure out what sets this idle

You could try looking on a MK2 forum for bits, just a thought..

choke is on for a lot longer than a few seconds, thats controlled by coolant temp and a heater. thats the housing on the passenger side with 2 coolant hoses to it. there is also a little more control provided by the pulldown unit, this stops the choke flap completely closing once the engine is running

the initial revs to 1500 or so is controlled by the plunger on the 3/4 point unit, which in turn is controlled by the TTV on the back of the carb.

the revs after 3/4 is in the running position are controlled by the waxstat. take it off and drop into a pot of boiling water, then watch the pin. it should extend, if it does not you need a new one.

also this apparently can 'reset' the wax inside it, though i think this only works if there is insufficient coolant flow due to the age old coolant manifold o'ring 'cats arse' syndrome
http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=95149

ha ha love the description of the o-ring

my car only seems choked for the first few seconds after start up, it seems lumpy/choked up then levels out smooth before the idle increases but i assume this is more due to everything being cold

so there is no adjustment on the 3/4 point unit at all, i take it the grub screw on the front controls the idle when all the above has finish and the car is running normally  

i admit that is one thing i have to left to do, the o-ring, i have done the waxstat after reading your 2e2 guide and that seems fine.
would lack of coolant due to the o-ring affect the 3/4 point unit i know they all have to work together for an ideal system but the auto choke housing gets warm in a matter of minutes to the point were you cant touch it, i would be surprised if there wasnt enough coolant getting through but you never know

there is a little adjustment on the 3/4, but tyou just set it so that when its in the running position the plunger is extended the distance it should be, if its sticking out the right amount when its in the running position then there is nothing else you can (or should!) do with it

one quick n dirty waxstat test, take it off and manually push in the plunger it is supposed to press against when the idle goes mental. if you can successfully bring it down to where you want it, this would suggest the waxstat is not working right, or someone has fiddled with the linkages inside the carb and buggered everything up for you

the haynes 2e2 manual i linked you to earlier has in-depth infoermation on how to reset all the linkages, so if you suspect someone has been at it underneath its time for you to take it off and have a damn good look!

it may be there is some coolant flow, but not as much as there needs to be if you know what I mean?  feel the autochoke housing, and at the same time feel the metal coolant pipe on the side of the engine, they should both heat up at just about the same speed

i might have a go at the waxstat one this weekend, i have done the water test and it extended fine but it would be nice to see it working on the car
although i am removing the carb this weekend hopefully to do the o-ring so i can give it a once over, i think i need to start at the beginning so the o-ring has to be done.
i can also check the measurment of the 3/4 point unit and see what adjusts the plunger.
I need to sort it really because as you say i dont really know who has been fiddling,i brought the car £102 full resprayed shell and a van full of the rest about 6 months ago (gorgeous helios blue paint job, full stoneguard and waxoiled) :mrgreen:  i put it all back together and it flu through the MOT last month and aside from this niggly cold start problem everything is perfect, not really knowing the history of the car i dont know if something has failed or been fiddled with.
i will let you know after this weekend ( i only get weekends to work on it)