How to Tune VW Dual Weber Carburetors

A dual Weber is a special type of carburetor used on some VW automobiles prior to the invention of electronic fuel injection. The Weber carburetor uses vacuum pressure to draw in outside air and mix it with fuel before delivering it to the engine cylinders. When the carburetor is not tuned properly, you will experience a rough idle. Fortunately, the problem can be corrected.

Things You'll Need

• Cross-point screwdriver

Instructions

1. Open the hood and locate the four adjustment screws on the base of the carburetor assembly. The duel Weber carburetor design consists of two Weber carburetors side by side.

2. Turn the engine on and wait for it to reach its normal operating temperature. This may take 2-5 minutes, depending on your vehicle. The water-temperature gauge on your vehicle's dash will read midway between the "low" and "high" mark when the VW reaches its normal operating temperature.

3. Start to turn the carburetor screws clockwise or counterclockwise with a cross-point screwdriver until the tachometer on your VW's dash reads 800 RPM (or close to it). This is the ideal speed for most VW vehicles at idle. Turn the screws evenly. For example, turn each screw 1/4 turn clockwise or counterclockwise and then check the idle speed. The key is to turn each adjustment screw to the same degree.

References

• "Auto Repair For Dummies; Deanna Sclar", IDG Books Worldwide; 1999

Resources

• Volkswagen Service Manuals