fast idling pierburg 2e2 .. waxstat ?

[al_b]

Happy new year !
It would be even happier if our trusty old golf (rolf) was in better health.. can anyone help I wonder ? has got the following symptoms :

fast idle (around 25000 when warm, peaking at nearly 30000 when engine cold)
engine over-running / coughing spluttering after ignition switched off.
apart from that, the old boy is in perfect health.

this suddenly started happening a couple of days back, half way through a long journey.. was cold out, but idle speed was fine to start with.
from what I've read it could be the waxststat, but anyone know of other things that could be the culprit ? or is that opening a can of pierburg worms ...

Had a quick look at the carb with a neighbour yesterday, and found the waxstat;  seems easy to get one bolt off the blighter, but the other one is hard to get to - don't really want to remove whole carb if I can help it.. anyone have a good tip ?
thanks in advance for any advice
roll on 2009
 

[Jay]

Also check the warm air feed pipe.

I think you've also added in an extra 0 above, you might want to edit your post before the pedantic bunch get here.

[Dolly]

30000  formula 1 eat your heart out..

just kidding, mine used to idle around 1800rpm got it down to 1100 by sorting the hot air feed, and replacing the vac hoses to the carb as they were split/leaking. but alot of people did mention a "wax stat" which could cause high idle.

sold it before i got round to sorting it fully.

[al_b]

ha ha yeah sorry!.. was getting a bit too handy with the zero's..must have been the pre new year excitement ..
thanks for that, I'll check the warm air feed too 
 if anyone does have any tips on removing / testing the old waxstat also, would be much appreciated 

[Jay]

Have a read over this thread by Rubjonny, it should help you a bit and after a quick read of the waxstat, I rekon it might just be that.

http://www.golfgtiforum.co.uk/index.php?topic=18871.0

[al_b]

cheers 
ah yes, the man himself ! he helped me find the problem with my rear window demister
was driving me crazy that..

back to the carb>  It has always idled fine at around 900 (got the zero's right that time) when warm (had the car 3 years now), just suddenly went up to 2500 the other day..
reading that thread & others, symptoms do seem to point to the waxstat.
just not sure the best way of getting it off without pulling out the whole carb (?) one bolt is really hard to get too & both seem seized up..
any tips anyone?

[rubjonny]

Just take the carb off, its really not as scary as it sounds, 3 bolts and the whole thing comes right off
Dont flip it upside down though as it'll dump fuel everywhere.  Gives you the chance to check the mounting flange over too!

However having said that, I'm not so sure the waxstat is to blame, since you said it came on all of a sudden, I'd be more inclined to think the issue is the 3/4 point unit malfunctioning, especially with the over-run issue combined.  Check round the back for any loose or degraded vacuum hoses, and also check the 2 electric thingies bolted to the rear of the carb.  You should hear a loud click come from them when the ign is turned on

If you watch the 3/4 point unit it should be fully extended 14mm when the engine off, then it should witdraw to around 8mm a few seconds after the engine is started.  Then when you turn the egine off the plunger should fully retract for a couple of seconds, then extend fully again (helps cut the engine out)

While I'm here whats the fuel economyt like, and how does it drive cold?

[al_b]

Hey jonny  cheers for that
ok I'll check the 3/4 point distance & listen for that click before I go any further I guess - then I'll have a go at getting the carb out !

fuel economy did seem ok really before this problem - not sure what it should be but could get a round trip to norwich from brighton (about 350 miles) out of about 40 quids petrol (is but a simple 1.8 GL - apologies for using this gti forum - only place I could find with the right info !), if you mean since this problem > not driven it much since then so couldn't say ..

driving from cold > have noticed for a while now (before the current idle problem appeared)that just after starting if I accelerate hard then engine seems a bit 'bumpy' (for want of a better technical term !) that soon goes, but on first start it usually does this for a minute or two..

[rubjonny]

It should be nice & smooth from cold, its possible you are starting to get a blocked coolant channel o'ring, but generally with this it runs rubbish for ages then over-revs.  If you feel the autochoke housing after a short run it should get proper boiling hot, basically it should be as hot as the engine  block and the other coolant hoses as it gets a direct flow of coolant out the back of the head via the inlet manifold

It may be something as simple as a bust choke thermoswitch or heater element inside the choke itself, both easy to test/fix as per de faq

[al_b]

ok, here's where I'm at now (!)
freezing cold ! (as is everyone I know), and with no garage to work in (subzero roadside tinkering can only go so far..) & much needing a car that runs well at the moment>  after testing waxstat, thermo switch and autochoke, but reluctant to pull anything else apart for now due to above reasons & also not having the time (!) I gave in & took it into my friendly independent vw garage - who have tried to fix it, but gave up after a few hours.. and charged me nothing for their trouble (good lads).
They have advised fitting a manual choke conversion to the blighter, or a weber.
They tell me this would clear up any problems related to this idling issue, and any future things that might go wrong with this age/type of auto choke system> coolant flow from manifold etc. inc  if the o ring has swollen and broken..

Anyone know of the manual choke conversion kits and how good they are ? am seriously thinking this is the way to go to avoid a lot of headaches both now & in the future (wanna keep this car going for a while as it is great apart from this..) 

hope someone is warmer than me..  spanish mike probably (!)