Auxiliary Air Valve or AAV (Component of K-Jetroinc CIS Fuel injection on 8v EV

April 27, 2020, 06:44:01 PM

Thanks to eddypeck

This is a part of the Bosch Contentious Injection System (CIS) otherwise referred to as K-jetronic (k-jet) systems. Found on UK 8v GTIs between 1984-1987, CIS was used in other models around the world as either K-Jet or KE-Jet. The 16v also used the K-Jet system however these were different to the 8v by way of having an ECU. The AAV was not present in the 16v setup, instead was replaced by the elecrtonically controlled Idle Stabilisation Valve (ISV).

It is mounted on a small bracket within the inside curvature of the inlet manifold.

Item 19 on the top picture:

Product information
During the startup phase, the auxiliary air device provides additional air so that, together with the additionally supplied fuel, the greater friction of the cold engine can be overcome.
An aperture in the auxiliary air device controls the amount of air that flows through. It is installed on the engine to absorb its heat. It is also electrically heated to track with the engine characteristic. The hotter the engine, the less additional air is provided.
The auxiliary air device is therefore a functional component of the fuel injection system.

Benefits
reliable start with cold engine

Bosch part numbers
Bosch part number Replacement number
0 280 140 145 - - - - - F 026 T03 050
0 280 140 146 - - - - - F 026 T03 050
0 280 140 164 - - - - - F 026 T03 051
0 280 140 165 - - - - - F 026 T03 051

External numbers
Vehicle make - - - - - - - - External number - - - - - - Bosch part number
VW (Volkswagen) - - - - - 049 133 453 - - - - - - - - F 026 T03 050
VW (Volkswagen) - - - - - 049 133 453 E - - - - - - - F 026 T03 051