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34adm weber idle really high?

Posted: Sat May 28, 2016 5:29 pm
by DejanLazarov
I have a 34adm on my 4g54 2.6 and even with the speed screw fully out, the idle is around 1200 rpm?

Anyone have any solutions? Tried searching the forum but couldn't find anything on this weber.

Thanks.

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 6:11 pm
by mstrrab1992
Timings correct? Make sure the throttle cable/accelerator pedal is causing it

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 6:41 pm
by DejanLazarov
Timing is at 8 deg btdc and was set afew nights ago. I tried completely removing the cable as a test and still nothing.

Ill recheck the timing when i get home but shouldn't of changed since 2 nights ago. Is there any other adjustable screws or anything?

Thanks for the reply =)

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 7:22 pm
by mstrrab1992
http://holdenpaedia.oldholden.com/Weber_Conversion

Check out that website scroll down till u find the 34adm carb it tells u the screws it has etc might be of use. Only other thing I can think of is possibly something to do with vaccume.

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 7:35 pm
by DejanLazarov
Actually, when i fired the car up i forgot to put the vac advance hose back on and drove it for a day without it and only noticed today that it was not pluged in. I did put it back on, thats when the rpm shot up =/

Hope no damage was done...

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 8:23 pm
by mstrrab1992
Are the 34adms vaccume secondary? If they are putting a vaccume on the vaccume secondary with the car constantly pulling vaccume can make it idle high, but I'm not a wiz with carbs. But I haven't messed around much with 34adm.

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 8:53 pm
by DejanLazarov
No clue man, all i know is that it has a vac line going from the dizzy to the carb. Its just weird that after i plugged it back in, it started to idle high...

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 9:37 pm
by Superscan811
The vacuum going to the carb secondary butterfly is different to the dizzy.

The dizzy uses manifold vacuum where as the carb secondary butterfly should use PORTED vacuum.

The basic difference between the 2 is that at low throttle position, the PORTED vacuum is at atmosphere (zero vacuum).

Another thing to look at is the adjustment for the secondary butterfly.

There is a cam arrangement that holds the secondary butterfly closed at low throttle. If you use manifold vacuum and there is a little play in that cam mechanism,
as mstrrab1992 said, it will cause the engine to idle high.

Cheers.

Re: 34adm weber idle really high?

Posted: Sat May 28, 2016 11:23 pm
by DejanLazarov
Dave, you were right!!! These people know ALOT hahaha isnt there a button i can press to fix the issue? Lol

Nah guys, thanks for the help, ill check in the morning and let you guys know. But everything was fine until i took these stupid balance shafts out =/

Only difference between when the car was fine and now is that i didn't notice the vac advance hose from the dizzy to the carby was not hooked up. I hooked it up and its still the same.

Cheers guys.

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 12:38 am
by DejanLazarov
So... from the dizzy (looking at the engine from the front of the car) the vac hose is going to the bottom right of the carb. From the rocker cover, the vac hose is going to the bottom left of the carb ( still looking at the engine from the front). Everything is the way it was before. Is it possible that something might have failed or is clogged up?

Can the UFO looking thing ontop of the dizzy (vac advance) fail not being hooked up for a day? I dont know too much about carbs etc... currently learning haha. This is a whole different world to fuel injection but sorry, nothing beats the carb sound under full throttle :z

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 8:56 am
by mstrrab1992
I doubt you would have stuffed anything, my guess would be you have a vaccume hose around the wrong way, itd be good if you could get a phew pics of the carby and the vaccume hoses, then can try to see what's going on, balance shaft removal wouldn't cause this. Something was just probably missed which unfortunately is very easy to do if you haven't dealt with it numerous times, only reason I know sorta what's going on because I've made that many mistakes its not funny haha.

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 2:36 pm
by DejanLazarov
Image

Image

Image

On the third photo, the screw you see that goes into the choke (i think its choke) was not going all the way in. I bent it a little so it passes the gear like thing inside and my idle is all good, but, i think the choke now does not work ahah any ideas?

Cheers.

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 5:49 pm
by mstrrab1992
That's your fast idle

#11 Fast idle screw. Adjusts the fast idle speed. Operates whenever the choke is partially closed. There are several steps of fast idle due to the operation of a stepped cam inside the choke mechanism. Adjustment should be made for fast idle on the first step after a cold start. Do not use this screw to adjust the normal idle speed.

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 5:51 pm
by mstrrab1992
Just to confirm, it would idle at 1200 when it was at normal operating temp? Because if its cold it should idle high till the choke comes off. Don't tell me we all just had a derp moment LOL

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 6:50 pm
by DejanLazarov
Hahahaha yer man, when its at operating temp, its at 1200rpm.

If i make the screw so it hits the gears inside, the car idles high. If i bend it so it slips past the gears, idle is perfect.

Re: 34adm weber idle really high?

Posted: Sun May 29, 2016 10:26 pm
by mstrrab1992
Maybe the choke isn't coming off?

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 12:15 am
by DejanLazarov
Hmmm could be actually. What could cause the choke to stay on?

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 12:24 am
by mstrrab1992
Maybe its faulty or maybe its been disconnected accidentally somewhere?

Electric automatic choke mechanism. Under the green plastic cover there is a heater element and a bi-metallic spring. +12 Volts is applied to the threaded stud in the centre when the ignition is on. The heater element heats up and in time, causes the bi-metallic spring to rotate the choke shaft, causing the choke to open. Loosening the three screws allows the cover to rotate, to adjust the choke to the correct fully open position after warm-up.

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 12:25 am
by Superscan811

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 12:26 am
by mstrrab1992
Good way to check turn the ign on and wait a bit and take the carb hat off and look inside to see if the choke is opening

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 2:30 am
by DejanLazarov
Thanks so much guys! Ill check in the morning and let you guys know =)

Cheers.

Re: 34adm weber idle really high?

Posted: Mon May 30, 2016 4:21 pm
by DejanLazarov
Choke is working ( closed when warming up, open when warm) and also rpm is increasing, but, thats with the screw bent to hit the gears which results in high idle AFTER the car is warm. If i bend it so my idle is good, choke still working (closed and slowly opening) but my rpm is constant and not going up as it should on cold start.

Re: 34adm weber idle really high?

Posted: Mon Jun 06, 2016 9:24 pm
by DejanLazarov
Took the weber out today due to me doing a turbo build (build log in engine section) and noticed something....
Image

The little spring in there had come off and was jamming the little gear inside! im assuming my issue is now fixed and im posting this incase someone else has similar issues. Thanks for the help guys =)

Re: 34adm weber idle really high?

Posted: Tue Jun 07, 2016 5:40 pm
by 75wagon
Well, that would explain it.

Dave...