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Poor Performance/Mpg -Fuel Rack Position Sensor Test (07.1/16)

Publication date: 1987-12-01
Reference number: 07.1/16

POOR PERFORMANCE/MPG -FUEL RACK POSITION SENSOR TEST

POOR PERFORMANCE/MPG -FUEL RACK POSITION SENSOR TEST

TECHNICAL SERVICE BULLETIN

Reference Number(s): 07.1/16, Date of Issue:  December 1987

TESTING FUEL RACK POSITION SENSOR

Model(s): 1985-87 300D

1985-87 300TD

1986-87 300SDL

1987-88 190D

Group: Engine Performance

Bulletin No. 07.1/16

Date: December 1987

Symptom: Poor Engine Performance/High Fuel Consumption

SERVICE INFORMATION

In case of customer complaints regarding poor engine performance or high fuel consumption, perform the procedure outlined in this bulletin, observing the test conditions listed below.

Test conditions

  • Coolant temperature approx. 80°C (176°F)
  • ACC system off
  • Accelerator control linkage correctly adjusted

PROCEDURE

  1. Connect socket box tester to EDS control unit with test cables. Connect multimeter to sockets 3 and 11 of socket box tester. See Fig. 1.
  2. Disconnect boost pressure line (arrow) from aneroid compensator (103) shown in Fig 2 . Connect vacuum pressure tester to aneroid compensator (ALDA) and apply 1000 mbar of pressure.
    NOTE: The steps to record V1 and V2 are not to last longer than 5 seconds each and there must be a two minute pause between those steps.
  3. With 1000mbar of pressure applied, start engine with selector lever in "P" and parking brake applied. Press firmly on brake pedal, place selector lever in "D". Apply full throttle for no more than 5 seconds at 1500-2200 rpm and record the voltage (V1) indicated by the multimeter. Release throttle and place selector lever in "P".
    Fig 1: Socket Box Tester Connections
    G91F32305
  4. Disconnect boost pressure line from aneroid compensator so that the pressure line is open to atmosphere.
  5. Apply parking brake. Press firmly on brake pedal, place selector lever in "D". Apply full throttle for no more than 5 seconds at 1500-2200 rpm, record the voltage (V2) indicated by the multi- meter. Release throttle and place selector lever in "P".
  6. Continue with test procedure.
Fig 2: Boost Pressure Line Location
G91G32306
Fig 3: DIAGNOSTIC PROCEDURE TABLE
GB0015619
VOLTAGE VALUES (V1 AND V2)

VOLTAGE MEASURE- MENT RPM PRESSURE ON ALDA (mbar) ALTITUDE ABOVE SEA LEVEL (ft) POSITION OF FUEL RACK LEVER VOLTAGE ON FUEL RACK POSITION SENSOR
V1 1500-2000 1000 Full Load 3.27 +/- .08
V2 1500-2200 0 Full load 2.45 +/- .10
1500-2200 300 Full load 2.43 +/- .10
1500-2200 700 Full load 2.42 +/- .10
1500-2200 1000 Full load 2.40 +/- .10
1500-2200 1300 Full load 2.39 +/- .10
1500-2200 1600 Full load 2.37 +/- .10
1500-2200 2000 Full load 2.35 +/- .10
1500-2200 2300 Full load 2.34 +/- .10
1500-2200 2600 Full load 2.32 +/- .10
1500-2200 3000 Full load 2.31 +/- .10
1500-2200 3300 Full load 2.29 +/- .10
1500-2200 3600 Full load 2.28 +/- .12
1500-2200 4000 Full load 2.26 +/- .12
1500-2200 4300 Full load 2.25 +/- .12
1500-2200 4600 Full load 2.23 +/- .12
1500-2200 4900 Full load 2.22 +/- .10
1500-2200 5300 Full load 2.20 +/- .10
SPECIAL TOOL INFORMATION

Tool Name Tool Number Group/Category
Socket box tester 124 589 00 21 00 83/B
Vacuum pressure tester 201 589 13 21 00 42/C
Test cable 124 589 33 63 00 83/B
Elec. connection kit w/carrying case 201 589 00 99 00 54/B
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