Adjusting A Weber Dgv 32/36

[djwarp]

So i have a weber carb i was wondering what is the right way to tune it ... every time i turn the truck on it requires me to keep pumping the gas for like 5 mins  any idea why it might be doing this?

[DanielC]

The engine probably need a full tune up.   Adjusting the carb is the LAST thing you do in a tune up, because everything else affects the carburetor.

Check compression.  Adjust the valves.  Set the timing, and if you are still running a point distributor, adjust point gap, or set dwell before adjusting the timing.

Make sure there are no manifold intake leaks.  Check all the vacuum hoses.  PCV valve good?

 

After everything is checked, and good, then you can adjust the carb.  Is the carb old enough that throttle shaft bushings are worn?  make sure the float level is correct.  Does the accelerator pump in the carb work?  with the engine warm, use a vacuum gauge to get the highest vacuum at idle.  Keep the idle RPM down, about 700 RPM.  Too fast an idle starts opening transition ports in the throttle body of the carb, and that changes off idle throttle response.  Too fast of an idle also makes it impossible to set the timing at idle, causing more problems.  All that has to be in specifications, on a warm engine.

 

To start a cold engine, Carb engine use a choke.  Stock choke on a 521 is manual, I do not know how your carb is set up.  If you have an electric choke, you can adjust the opening and closing of the choke for the temperature.  When the choke is activated, manually, or automatically, there is also some linkage that opens the throttle.  You can adjust the amount of throttle opening to choke by bending the linkage.

[Elkie]

can try this first.

 

http://www.carburetion.com/Weber/adjust.htm

 

then troubleshooting

 

http://www.webercarbsdirect.com/v/vspfiles/images/Weber%20Trouble%20Shooting%20Guide.pdf

[oldskoolvws]

I'm guessing choke.

[dat521gatherer]

Yes sounds like no choke.

[5t341tH]

i also have this problem with my weber. i see the choke plate closed during cold starts. but with the plate closed, the engine runs so bad that it will die. and i get black smoke coming out the tail pipe. so i have to leave the choke plate open always for it to "warm up"