The RB30 engine uses different engine control and electrical components than the more popular TB42.
Sometimes, I have found it difficult to locate items on and data for my vehicle. Feel free to post any information and/or helpful hints or experiences regarding the maintenance and repair of the RB30.
Fuel Return Solenoid.
If the engine wants to flood at Idle, maybe the fuel return solenoid isn't functioning properly.
There is an Engine Revolution Sensor Unit which is fixed to the metal end under the Drivers Side of the dash. It receives an RPM signal from the coil through a resistor which is cable tied or taped to the top radiator hose. The Engine Revolution Unit supplies a signal to the fuel return solenoid.
The circuit is on page 12-15 of the Haynes manual.
With Ignition off. Unclip the return fuel solenoid connector and check the resistance of the solenoid with a multimeter. It should have a resistance of between 20 to 25 ohms.
If you intend to check the operation of the circuit live, dig out the rubber grommets which seal the wires at the connector. Insert the meter probes and set it to volts.
With the engine running, the voltage readings to the solenoid are: at idle 12 to 14 volts and zero volts above 1450 rpm, (you should be able to hear it click in and out).
I used some some silicon to reseal the wires, making sure no silicon is between the wires, so there is no chance of current tracking between the two.
The Fuel Return solenoid is situated under the top radiator hose.
Added info below from Dom14.
RB30 Facts, Figures and Helpful Hints - Hyperlinks to specific areas of the thread.
Fuel Return Solenoid
Fuel Pump Control Unit(FPCU)
Engine can't achieve high revs
Engine coolant drain plug
Speedo Problems and Adjustment
Ignition Auto Advance Vacuum Diaphragm (Poor Performance and Fuel Economy ).
Testing for a blown head gasket
Air Intake Pre-heat assembly fitted to a stock RB30S
Reasons for Backfiring
Heater core blockage cleaning method on a GQ Patrol
instrument panel circuit for an RB30S
RB30 Patrol(or any vehicle) Universal Joint(s) Replacement
RB30 Vacuum line diagram and related components
RB30 Patrol Coolant flow diagram(s)
RB30-TB42 Nikki carby tuning procedure(temporary)
Carburetor lean/rich diagnostics
A useful modification after snorkel installation
Fan Clutch test
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