Rover's Vikingship Testing the EFi System
part II
Rover's Vikingship

Test 9 Voltage of throttle potentiometer

Test no. 9  (5,2 kB)

ECU multiplug connected
Ignition ON
Voltmeter connected between yellow and green wire at the multiplug

Voltmeter should read 4.3 +/- 0.2 Volts (ECU control voltage)

If zero or lower reading check:

  • Wiring and connections
Measure between the yellow and red wire.
Voltmeter should read between 0.325 +/- 0.025 Volts

If incorrect, reset the potentiometer:

  • Slacken the potentiometer body screws and rotate the body until the meter reads 0.325 +/- 0.025 Volts,tighten the screws
Slowly open the throttle the injectors should be heard to operate and the Voltmeter should register a smooth increase up to 4.5 Volts maximum.

If the voltages can't be obtained or if the voltage is erratic when the voltage is opened.

  • Renew the throttle potentiometer. Often the potentiometer is worn at the lowest (idling) part of its path. This causes unregular idling with revs going up and down.
If OK continue with Test 10

Test 10 Resistance of temperature sensor

Test no. 10  (7,2 kB)

WARNING! only connect the ohmmeter for a short period. the ohmmeter will heat up the winding and give an incorrect reading as time goes

ECU multiplug DISconnected
Ignition OFF
Ohmmeter connected between pins 6 and 27

TemperatureOhms
-10 C +/- 0.5 C8.26 to 10.56 Ohms
+20 C +/- 0.5 C2.28 to 2.72 Ohms
+50 C +/- 0.5 C0.76 to 0.91 Ohms
If Ohmmeter readings are incorrect:
  • Try to find another temperature sensor with the right spec's and place it into the air filter housing with the wires reconnected or replace the air flow meter
If the readings are correct. Repeat the resistance check at the ECU harness pins 6 and 27 to check continuity

If the readings are incorrect,check:

  • Red & Brown wiring (RB) and connections
  • Blue & Red wiring (UR) and connections
If OK refit the ECU multiplug cover and continue with Test 11

Test 11 Resistance of coolant temperature sensor

Test no. 11  (4,8 kB)

A faulty coolant temperature sensor can cause black plugs and excessive fuel consumption. The ECU thinks the engine is cold if the connection is faulty.

WARNING! only connect the ohmmeter for a short period. the ohmmeter will heat up the winding and give an incorrect reading as time goes

ECU multiplug DISconnected
Ignition OFF
Measure coolant temperature with a thermometer
Disconnect the sensors socket
connect ohmmeter between the terminals

The readings should be:

TemperatureOhms
-10 C 9100 to 9300 Ohms
0 C 5700 to 5900 Ohms
20 C 2400 to 2600 Ohms
40 C 1100 to 1300 Ohms
60 C 500 to 700 Ohms
80 C 300 to 400 Ohms
100 C 150 to 200 Ohms
If Ohmmeter readings are incorrect:
  • Remove the sensor and check it again in melting ice and water (0 C) and boiling water (100 C)
If the readings are still incorrect. Replace the temperature sensor and rechek
A temporary solution for the problem is to connect a resistor of 175 Ohms across the sensors connection when the engine is hot. Remove the resistor when the engine is cold.

Resistor  (4,4 kB)

If the readings are correct reconnect the temperature sensor and check the resistance at the ECU pin 13 and the earth.

If the readings are incorrect check:

  • Black & Slate (BS) wiring and connections
  • Black & white (BW) wiring and connections
  • Earthing
If OK continue with Test 12

Test 12 Resistance of the Extra Air Valve

Test no. 12  (6,1 kB)

ECU disconnected
Ignition off
Ohmmeter connected between pin 87 of the fuel pumprelay and pin 34 on the ECU multiplug connection.

The Ohmmeter should read between 30 and 40 Ohms.

If readings are outside these limits. Renew the extra air valve.

If Ohmmeter shows infinity check:

  • White &purple (WP) wiring and connections
  • Red &Blue wiring (RU) and connections
If OK continue with Test 13

Test 13 Resistance of the Cold start injector

Test no. 13  (6,5 kB)

ECU multiplug disconnected
Ignition OFF
Disconnect the thermotime switch and temporarily connect the purple and blue wire (PU) to the earth.

Measure the resistance between the ECU multiplug pin 4 and the earth.
The resistance should be 0 to 5 Ohms.

If the reading is incorrect check:

  • The temporary earth for good connections
  • White & Red (WR) wire and connections
  • Purple & Blue (PU) wire and connections
If the reading is still incorrect, disconnect the cold start injector and check its resistance.
The resistance of the injector should be 0 to 5 Ohms.

If incorrect renew the cold start injector

If OK continue with Test 14

Test 14 Voltage drop injector circuit

Test no. 14  (9,8 kB)

ECU multiplug disconnected
Ignition ON

Warning! The Voltmeter must be connected for a short time only because fuel will be injected during the test!

Connect the voltmeter between a good earth and each injector ECU multiplug terminal in turn.
Check the voltage reading for each injector
Compare the injector voltages. These should not vary by more than 0,5 Volt

If the variation is more than 0,5 volt continue with Test 15

Test 15 Resistance of injector circuit

Test no. 15  (9,6 kB)

ECU multiplug disconnected
Ignition OFF

Connect the ohmmeter between terminal 87 or 87A of the main relay and each injector ECU multiplug terminal in turn

A reading of 7-10 Ohms indicatesNo fault
Infinity indicatesA broken connection or component
A high resistance reading indicatesA poor connection,faulty wiring or faulty injector or resistor

If a faulty injector or resistor is suspected continue with test 16

Test 16 Resistance of injector circuit (2)

Test no. 16  (9,0 kB)

Disconnect the harness multiplug from the resistor pack
Connect an ohmmeter between terminal 9 and terminals 1,3,5 & 7 on the harness multiplug to check the values for injectors 1,3,5 &7.

Do the same between terminal 2 and the terminals 4,6,8 & 10 for those injectors.

The values should read 6 Ohms +/- 1 Ohm.

If any value is incorrect replace the resistor pack

If all is OK

Disconnect the wiring from each resistor an check its resistance value by connecting the ohmmeter between its both terminals

The resistance value for each resistor must be 2.4 Ohms at 20'C +/- 0.5 Ohm
Renew any injector outside this resistor range

 

END OF THE TESTS !!

With these last tests you should have located the problem in your injection system. If the engine still isn't running or running uneven the problem probably won't be the fuel injection but the ignition or something mechanical.

SD1 injection....The basics

SD1 injection....The Airflow meter

SD1 injection....Testing the EFI page no. 1



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