Bosch 2008 - Manual (Page 44)

A 42 | Gasoline injection components
Bosch Automotive Aftermarket 2008 | 2009
Pulse valves
System:
K-Jetronic (with Lambda control)
Purpose:
The pulse valve is installed in the connecting line between the fuel distributor’s lower chambers
and the fuel return. It is actuated by the Lambda controller and opened and closed in a defined
cycle. This enables the pressure in the lower chambers to be varied and the air/fuel mixture
regulated to λ = 1.
Part number:
0 280 150 300 – 0 280 150 349
Secondary-air pump (electrical)
System:
Motronic
Purpose:
Use is made of the electric secondary-air pump to comply with the stringent emission legislation
in the post-start phase. Fresh air injected directly downstream of the combustion chamber
causes afterburning of the hot exhaust gases and ensures more rapid warm-up of the catalytic
converter.
Part number:
0 580 000 ...
Shutoff valve
System:
Motronic
Purpose:
The shutoff valve is used in turbo engines to protect the turbocharger. The turbocharger
remains in operation on switching from turbo to overrun mode. Without a shutoff valve, the air
would impact against the closed throttle valve and flow back into the turbocharger. This return
flow of air could damage the turbocharger. To guard against this, the seat of the shutoff valve
is opened by the vacuum applied in the intake manifold in overrun mode with the throttle valve
closed. This enables the air conveyed by the continued operation of the turbocharger to be
routed via a bypass around the turbocharger and back into the intake manifold.
Part number:
0 280 142 100 – 0 280 142 150