engine and drivetrain Unidentified Jet On Weber 32/36

[adavis]

What is the jet circled in green?  And what is the correct setting?  I have looked at every diagram on the internet and can't find what it is.  Anyone?

 

[Cru Jones]

Looks like the idle adjusting screw. Part #58 on the below diagram. Not sure right off what the default setting is.

 

[adavis]

So there is an idle mixture screw and an idle adjusting screw?  What is the difference?

[adavis]

The diagram above doesn't have the screw shown in my picture.  I can find other carbs with the same pic, but not the diagram.

[adavis]

Here is another carb showing the idle mixture screw and the mystery screw just to the right of the post holding the return spring.  Help please

 

 

[Hans]

Idle mixture adjusts mix of air and fuel at low end, idle adjustment sets idle speed. As I recall, you set to default positions, then you adjust mixture first.

Idle mixture adjusts mix of air and fuel at low end, idle adjustment sets idle speed. As I recall, you set to default positions, then you adjust mixture first.

[adavis]

Here is above diagram with circles: 

blue = idle mixture

black = idle speed

red = ???

 

 

[jimk]

Not having run a carb in 7 years, but that looks to be the fast idle speed when the choke is on and the fast idle cam is in contact with that screw.  Open the throttle a bit and finger close the choke plate the fast idle cam should rest on that screw.  Use it to set the fast idle speed when the choke is on.

[adavis]

I thought the fast idle screw was behind the choke.  The guy I bought the car from called the screw circle in red the idle adjustment, and screwing it in a bunch helped me pass emissions.  But I want to adjust properly now that the carb is cleaned up.

[Hans]

Fast idle is behind choke. Black and blue are correct. Can't remember what red is. What's in there?

[adavis]

I have no idea what is in there.  I don't really want to take the screw all the way out until I know what it does.  My Haynes weber manual doesn't mention it, and it isn't listed in any of the diagrams that I have seen. 

[Hans]

Does it turn in either direction- like the idle mix screw would? Or is it screwed in tight?

[adavis]

It is a mix screw of some kind.  I did screw it most of the way in when trying to pass emissions.  Now, I want to back it out to where it should be set but don't know what that is.

[Hans]

What car did it come from, or is it generic?

I know on the newer DCOE models there is an extra air screw on each barrel for adjusting base idle settings if there are big differences. The default setting is closed. If all else fails, twiddle with those. Not sure if that is the purpose on your model, but it feeds primary side, so could be. How did it run in the emissions position?.

[adavis]

I just got the car a few months ago and this is what came with it.  The specific model is 32/36 DGAV-33B-1.  It is made in Spain.  That's a good question on if it is the model for the 2002.  I'm not sure yet. 

 

It did pass with the screw most the way in, but the guy I bought it from had them out pretty far.  I didn't adjust the idle mixture when adjusting the mystery screw.  So now I wonder if I should back this screw out and turn in the idle mixture.  I wish I knew what this thing does.