Jump to content
Ultimate Subaru Message Board

Weber High Idle


Recommended Posts

Hello,

I have a 1985 GL hatchback, EA81, automatic 1.8l with emissions. I just put a Weber 32/36 carb on it (with the EA81 one piece adapter. 
 

I’ve plugged every vacuum inlet I can find (except PVC/EGR) and now when I start it it revs to 5k or higher. One day I adjusted the choke to be fully open (butterflies open) and it stayed around 2500. Adjusting the idle speed screw didn’t help. 
I have checked and adjusted the accelerator cable and I don’t see any linkage issues. 
 

please please help. 

Link to comment
Share on other sites

It is surprising just how many revs you can get from such a minimal opening of the throttle.

Looking down primary throat can you see if it is closing properly?

Is it a tried and tested Weber or out of the box newy?

Had issues with new before with idle screw jet only just holding on ( by some foam packing?)

Adaptor correctly seated between inlet and Weber?

PCV valve stuck open?

Link to comment
Share on other sites

The main jet was in all the way so I will back it out two turns. The adapter to intake manifold has jb weld all around it (paranoid of air leaks). 

The previous owner had put an autobest fuel pump on. I’m trying to get the model number but  could too much fuel pressure cause it to high idle? 
 

I have a return spring on linkage, looked down the primary with a light and it “looks” closed. Adjusted the choke so the butterflies are closed (maybe I shouldn’t). I did plug the two holes going into the sides of the engine....not sure if that was correct. 
 

Thanks in advance! 

Link to comment
Share on other sites

Those PCV ports need to be open.  Blow by has to have somewhere to go.  Has nothing to do with idle though.

The choke should only be fully closed when dead cold and cranking.  Once it fires, it should start to open.  If it's too closed [or too open] , it won't run well.  Once it is up to normal temp, the choke should be wide open.

Link to comment
Share on other sites

Yep, the air in the crankcase needs to exchange with outside world in a filtered way ( combustion ). Make or buy a catch can to run the 5/8" lines to catch can. I use heater hose. Also need to plumb in the PCV valve. Then use a smaller diameter hose in order to fit the Weber carb air filter fitting. I would fit two into air filter base to start to match the original 5/8" flow. So, catch can could have up to 3 of 5/8" fittings and  2 of 3/8

Edited by Step-a-toe
Link to comment
Share on other sites

12 hours ago, glsubby said:

The main jet was in all the way so I will back it out two turns. The adapter to intake manifold has jb weld all around it (paranoid of air leaks). 

The previous owner had put an autobest fuel pump on. I’m trying to get the model number but  could too much fuel pressure cause it to high idle? 
 

I have a return spring on linkage, looked down the primary with a light and it “looks” closed. Adjusted the choke so the butterflies are closed (maybe I shouldn’t). I did plug the two holes going into the sides of the engine....not sure if that was correct. 
 

Thanks in advance! 

I think you may have "main jet" and idle air adjust screw confused. Maybe it is me confusing with certain Holley 4 bbl ??

A few years since I have played but think main jet is inside and needs top section off to access, change.

You have primary barrel your choke sits above, then the secondary barrel that opens mechanically

Edited by Step-a-toe
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...