TheSamba.com :: View topic

Wed Nov 18, 2009 6:45 pm

Solex 34 PICT-3, Flange # 427-1
Bosch SVDA, 205

Has anyone experienced one of this carbs creating a vacuum at the SVDA port of 15 in. Hg @ 900 RPMs? Isn't it suppose to be closer to zero? When I set the idle at 900 RPMs, and then connect the vacuum line to the distributor, the RPMs jump to 1,500.

Wed Nov 18, 2009 7:17 pm

Are you using the vacuum port on the left side of the carb?

Some 34PICT-3s have a second/third port at the rear (rear of car). These are for the vacuum retard and other items.

If you are using the left side port, check you throttle plate setting. If the throttle plate is open too much, you will have vacuum at this port at idle.
Throttle plate setting is described here:
http://www.vw-resource.com/tune-up.html#idle

Wed Nov 18, 2009 7:21 pm

Yes it sounds like the screw on your throttle arm is not set right and screwed in too far.

Wed Nov 18, 2009 7:46 pm

That was it. The throttle valve screw was too far in. I could I see a tiny hole just visible just under the edge of the valve. When I loosened the screw, the valve covered it.

Tomorrow the carb goes back on the car. Thank you for your help!

Thu Nov 19, 2009 5:39 am

datatechnic wrote: That was it. The throttle valve screw was too far in. I could I see a tiny hole just visible just under the edge of the valve. When I loosened the screw, the valve covered it.

Tomorrow the carb goes back on the car. Thank you for your help!

Did you "adjust" the fast idle screw (aka throttle screw).. or did you just "loosen" it?

The mixture/bypass screw adjustments assume the throttle opening is adjusted properly.

Thu Nov 19, 2009 8:16 am

I loosened it until I could see space between it and the fast idle cam. Then I tighned it until it touched the cam, and then gave it another 1/4 turn.

I would have sworned that I had set it right before. When I re-install the carb I'll make sure the fast idle cam opens all the way when the engine warms up.