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Servicing Keihin carburettor>07.78 > < Checking automatic intake air preheating

Checking Intake Manifold Preheating for Optimal Performance

34 PICT, Keihin carburettor and ignition system
Air cleaner - Keihin carburettor
Checking intake manifold preheating

The intake manifold electrically heated up to a coolant temperature of +70 °C to improve mixture preparation during the warm-up phase.
 
U22-0001

Checking intake manifold preheater

  • ● Engine cold.
  • ● Voltage supply OK.
  • ‒ → Use hand multimeter V.A.G 1526 and auxiliary lead from V.A.G 1594 to measure resistance between connector and earth (-).
         Specification: 0.25...0.50 ohms.

Checking thermoswitch for intake manifold preheating
 
U22-0002
  • ‒ → Use hand multimeter V.A.G 1526 and auxiliary lead from V.A.G 1594 to measure resistance between connector.
         Specifications:

▸07.79:

below + 58°C

= 0 ohms

above + 80 °C

= infin.

08.79 ▸:

below + 60°C

= 0 ohms

above + 70 °C

= infin.

Servicing Keihin carburettor>07.78 > < Checking automatic intake air preheating