M110,  Mechanical gazoline injection system CIS

Checking delivery capacity of fuel pump



07.3—130 Checking delivery capacity of fuel pump


Test values


Voltage at fuel pump min.
11.5 V


Delivery capacity min.
1 liter/30 seconds


Special tool


Clamp for fuel hose
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000 589 40 37 00


Conventional tools


Voltmeter, graduated measuring glass or measuring cup (at least 1 liter), stop watch


Self-made fuel hose


Fuel hose
Tube with sealing cone
Coupling nut
500 mm long M 14x 1.5


Contact bridge
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07.3.2 Ha 130/1 F2




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1 Check delivery capacity of fuel pump during fuel return flow. For this purpose, unscrew fuel return hose (arrow) on fuel distributor.


2 Screw self-made fuel hose to fuel distributor and hold into measuring glass or cup.
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3 Check delivery:
Mixture control unit with safety switch
Switch-on ignition. Pull cable plug from safety switch in mixture control unit and put cable plug back again after 30 seconds.


Mixture control unit without safety switch


Pull off fuel pump relay and bridge the two bushings (wiring diagram 07.3—120). This will provide voltage for fuel pump.
Pull off contact bridge after 30 seconds.
Prior to September 1981: Jacks 1 and 2. Starting September 1981: Jacks 7 and 8.
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Model 123


Model 126
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07.3.2 I la—130/2 F 2




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4 If the delivery volume is less than 1 liter/30 seconds, check the following items:
a)  Check strainer in feed connection of fuel distributor for passage.
b)  Check voltage at fuel pump.
Nominal value = min. 11.5 Volts (with engine stopped).
c)  Check fuel lines for restrictions (squeezed lines).
d)  Pinch leak line between fuel reservoir and intake damper. Check delivery once again. If specified delivery volume is attained, replace fuel reservoir.
e)   Replace fuel filter.


5   If delivery volume is still too low, replace fuel pump.
6   Connect fuel return flow hose. Mount relay.


07.3.2 I la—1 30/3 F2