How to Check the Pulldown Unit Opel Vectra A

Pulldown Unit, Check

Pulldown Box, Check

Air cleaner, vacuum hose (1) and (2) from carburettor

Close connection (1),

connect Vacuum Hand Pump MKM-667 to (2), create pressure difference of 300 mbar/43.5 psi.

Pulldown box (3) for leaks

Pressure difference must remain constant, if not: eliminate leaks, if necessary, replace pulldown box.

Thermo Time Valve, Check

Checking conditions:

Thermo time valve (1) has approx. 20 °C/68 °F temperature, perfect current supply to wiring harness plug (2) - at least 11.5 volts.

Function of thermo time valve

Measure electrical resistance -

4.5 to 7.5 ohms at 20 to 30 °C/ 68 to 86 °F.

Connect Vacuum Pump MKM-667 and actuate - thermo time valve must have passage,

plug (2) on valve (1) - ignition switched on - ascertain switchover time - 4 to 10 seconds at

+20 °C/68 °F until increase in pressure difference.

If necessary, replace thermo time valve.