Hey, Right, can anyone tell me what needs connecting to where with respect to the vacuum hoses on a Weber carb on a 1.8 MK2 Golf. There are 2 metal pipes on the rear of the carb (bulkhead side), the top one has a short hose that runs back to a part of the carb, slightly above. The bottom pipe has a plastic cap over it - with this taken off it runs really rough and makes a loud hissing noise - I'm guessing there should be a vacuum hose from this to somewhere? Also...pumping the brake causes the idle to fall. Any ideas? Chris. Edited by: DarkAngel
The one on the back you mention as hissing should have a vacuum hose that connects it to the airbox. It connects to the rear of the two next to each other on the left side of the airbox. Cheers
I took lots of photos of the Weber before I took it out of my Driver, so I could remember the connections. Let me know if you want to see them.
Could be a vacuum leak from the brake servo to the inlet manifold. I had this problem though and it was a knackered servo and not the hose.
I have noticed anothe problem - after the engine has been running for a while pumping the brake pedal causes the idle to rise as well! Also....even after the engine has warmed up, and the choke is in, the idle tends to slowly drop off, then suddenly pick up again for a second or two, then drop off again! Any ideas!? Trev - the pics of your Weber would be useful!
DarkAngel I have the exact same problem and I just tried pumping the brakes and it did the same thing!! I have a weber on an 1800.
Can you hear any hissing? I removed the panel around the pedals and found the noise was coming from the servo. Worth a check.
I don't think the servo is the problem, as the pedal pumps up ok as it should do. I think I have a vacuum connection either wrong or missing, but I have no other carb to look at for reference as to where the hoses and connections go to! Chris.
Here you go Chris. I was out checking my oil etc. ahead of tomorrows rolling road tune, so took a few pics for you... You can just about make out 2 vacuum hoses, the upper one connects the choke pull down unit to the carb, and the lower one connects to the side of the airbox, as shown in picture 2... The right hand one connects to the warm air flap control unit on the end of the airbox inlet... Finally, the brake servo hose connection to the distributor vacuum unit... Cheers
Excellent, thanks very much for the photos - I think I can see where I'm going wrong, I will pop out now and stick everything where it should be! Chris.
Ok, I have no pipe running from the bottom vacuum connection on the carb to the airbox, so will pop up to halfords and get some hose. The hose between the distributor unit and the brake servo hose is connected between the distributor unit and the bottom connection on the brake servo hose. There is another connection above however, which has something stuck on to it, that looks like it plugs the second hole, putting it on has the same effect as putting your finger over the hole and makes the car idle nice and smooth. Am I right in thinking I have everything in place now?
Right, just sorted out the hoses and it seems to be running better now, it isn't idling up and down anymore which is good! Now, just need to tweak the idle slightly and it'll be running lovely! Cheers for the help. Chris.
I think the second hose connection on the servo hose was used for the pierburg vacuum system, long distant memory now. Mine runs nice and smooth with the vacuum connections pictured, or I should say used to before the Kent Cam. I can easily live wih a slightly dodgy idle though for the smile you get with the cam. Cheers
Mine idles really smooth with the Kent cam, i've got the idle set at 1000rpm and I just adjusted the air fuel mixture screw "by ear" i.e, to the highest engine rpm, runs great, it seems to fluctuate a tiny bit but doesnt cause any running issues, no vibration or anything.... unlike my cousins 2l 16v vauxhall, that runs like a bag of nails with his kent cams...
