Checking fuel pump

Measuring point

prior to pump inlet

Vacuum (suction end)

at starting speed mbar (mm Hg)

335-470 (250-350)

max. pressure drop within first minute mbar (mm Hg)

Measuring point

following pump outlet

Delivery pressure (pressure end)

at starting speed bar gauge pressure

0.20

max. pressure drop within first minute bar gauge pressure

0.05

Special tool

Clamp

000 589 40 37 00

e.g. made by Bosch, EFAW 177

Fuel pump pressure vacuum tester

e.g. made by SUN, VPT 212

1    Short ignition system. For this purpose, connect cable from ground to terminal 1 of ignition coil.

2    Pinch suction hose. Pull off suction and pressure hose.

Connect tester at suction end.

1    Suction hose

2    Pressure hose

07.2.2 Ib—210/1

3 Crank engine with starting motor until vacuum is no longer increasing. Compare indicated value with rated value. Watch pressure drop.

4   Connect tester at pressure end.

5    Crank engine with starting motor until delivery pressure is no longer increasing. Compare indicated value with rated value. Watch pressure drop.

Note: If the vacuum or delivery pressure is not attained, check whether infiltrated (false) air is sucked in at rubber sealing ring (1). Renew sealing ring, if required, and repeat test.

07.2.2 lb-210/2