Welcome to David and Janet Ribbans blog

We live in Adelaide, South Australia and enjoy travel in the Australian outback in our Oka 4WD motorhome, hence the blog title.

To quickly locate any of our more than 80 travel and technical articles, use the drop down menus below or scroll down the lists in the right hand sidebar. But please read the disclaimer first, we've tried to be accurate and current but things can change...
You can also visit the official Oka 4WD website here.

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We're now honoured to have our blogs archived
on the National Library of Australia's Pandora Web Archive.
Bookmark this link to the archived version in case anything ever goes wrong with Google, or I accidentally hit "Delete All" in a fit of pique. The drop down menus above might not work in the archived version but everything else should...

Sunday, 14 August 2011

Minimum Electrics to Start the Engine (Injector Pump Solenoid Fix)

On an Oka, there is only one critical electrical item which keeps the engine running or not, and that's the fuel cut off solenoid at the back of the injector pump. (Bosch call it the ELAB, electronic shut off device. This Bosch Instruction Manual is a very valuable resource on the VE pump).

As long as you can start the engine (maybe by bump starting it if you have no battery power or the starter has failed), that solenoid wire with 12v applied is the only electrical thing needed to keep it running and a even small 6v lantern battery would probably do.

Minimum Electrics to Start and Keep the Engine Running

Even if all dashboard "ignition" functions are disabled, connecting up the fuel cut off solenoid to 12v and hot wiring the starter motor to the battery (or batteries) should start the engine (in neutral of course with the park brake on since you'll be under the vehicle). The key is still required to unlock the steering though.

Connect the Start Relay connection on the starter relay body (a small terminal between 2 large ones) to the battery +ve to engage the starter gear (only a thin wire is required), and remove it when the engine starts. (One of the large terminals will be a battery +ve connection so only a short wire is needed, even a screwdriver would work).

If there's only a click, or nothing at all, the battery wiring is suspect so you may also need to use a thick jumper lead to connect the battery +ve to the main starter motor terminal (which is probably on the starter relay body, not the actual starter motor, follow the (red) wiring from the battery), but it should already be connected. The lead on our starter motor body is actually a (black) ground connection.

Also check that the battery -ve is effectively connected to the chassis or frame of the starter motor using the other jumper lead.

Disconnecting the fuel cut off lead will stop the engine (or it can be stalled in a high gear by gently letting out the clutch with the brakes on).

If the engine rotates but doesn't start, it's a fuel problem (or less likely, a major mechanical fault) and that could be the solenoid. But it could also be the lift pump, or you could be out of fuel, or have air or a blockage in the system so check out these and all other possibilities before accusing the solenoid.

What if the starter fails?

Another obscure fault we have had is an intermittent winding connection inside the starter solenoid on top of the starter motor body. This can prevent starting on an otherwise healthy vehicle and are not repairable items so a spare would be a wise investment (about $100). Pity we didn't have one when ours failed, we had to have one shipped from Perth to Eucla.


The solenoid with the dodgy connection, after I reflowed the solder to try and fix it.

The contactor inside can still be used to connect the starter motor by pressing the plunger on the other end

A possible bush repair in this case is to:

  1. remove the starter solenoid (three long philips head screws on ours and you'll probably need to remove the starter from the engine first),
  2. use a mechanical method (eg a rod with a slotted head tie-wrapped to the motor body) to pull the gear lever inside the housing backwards away from the housing (to engage the starter gear) and
  3. ensure the gears are in neutral and connect the starter motor connection to the battery +ve manually, using the internal solenoid contactor (and pressing in the internal plunger to bridge the contacts), a high current (300A+) relay (like the one for paralleling dual batteries) or or even a thick jumper lead. Connecting  batteries in parallel will help to drive the starter motor.

Jumper lead connections may spark a lot and weld themselves together so use a very thick steel bar to absorb the heat and wear glasses (using the solenoid contactor or relay captures any sparking), but the motor should now turn over and start the engine.

Quickly remove the connection or release the plunger as soon as it starts, and push the rod so the solenoid gear lever moves forward into the housing, disengaging the starter gear. The rod can be tie-wrapped to the motor body so that the gear can't accidentally re-engage.


The gear rod pulled forward to engage the drive

You would need to do this each time you need to start the engine so it's only an emergency fix, so leave the engine running during all short term stops and think about restarting options before switching it off. Doing this is a busy car park or on the road side would be potentially dangerous or frustrating.

If all else fails, the Oka can be bumped started quite easily. With a couple of people pushing, the Oka will roll quite well on a hard surface and 5 tonnes of Oka has sufficient energy to turn over the engine, even when moving slowly.

Checking the Fuel Cut Off Solenoid (not to be confused with the Starter Motor Solenoid)

I have rarely read or heard of a failed fuel cut off solenoid, whereas broken wires and terminals are commonplace, so check that it really is the solenoid first, before removing it. It should have a low resistance to ground, a few ohms (probably around 10 to 20 Ω, check it by connecting a 5W globe in series to +12v, it should glow if the solenoid coil is OK). If you can hear it click when voltage is applied it's probably OK too.


What if the Solenoid has Failed?

If the cut off solenoid itself really has failed (other than a broken terminal screw, and you could tape a wire to it to maintain contact), the engine can't start. I did think that removing the solenoid and using a magnetic pick up wand to engage the valve may work. However the solenoid valve also seals the rear injector port so removing it would allow fuel to leak out, probably under pressure, so that trick won't work. (See this photo of a disassembled solenoid valve and its location). In this case replacement or modification (see below) of the solenoid is the only answer. This is now on my list of "Things To Do If Desperate".

Fixing the Solenoid

One good suggestion I have seen (thanks to RedZerOne) is a simple modification to a failed solenoid to get the engine going:

"When mine went out two years ago, I gutted it rather than replace it. To do this, remove the solenoid from the VE pump [edit: 15/16 inch spanner] and remove the plunger and the spring from inside the solenoid. Double check in the pump and solenoid that there's no debris and reinstall the solenoid. This will allow the engine to have fuel constantly. It'll operate the same as if you had a working solenoid, the only difference is that in order to shut off the engine, you'll have to manually stall it out. I've been doing this for two years now with no problem."


Remove the spring and plunger and reinstall the solenoid

Photo courtesy http://bricofoy.free.fr/phpwebgallery/

Note, no electrics to the pump are required after this mod and the fuel will be permanently on, which doesn't matter except that the engine won't stop and would have to be stalled. However getting access to the solenoid might require removal or loosening of the top section of the pump, but if you're desperate enough anything goes.

[In fact if you can bump start the Oka after parking on an incline (I'm not sure how easy this is with a diesel, try 2nd or 3rd gear), you wouldn't even need any batteries after this mod to the solenoid. Caution, if you ever try this without batteries, disconnect the alternator first to avoid generating high voltages after the engine starts which could damage any electrical equipment. The batteries normally constrain the voltage to around 14v, even dead ones, but an unloaded alternator can generate up to 100v at very high power and can even be used as a welding supply].


This the solenoid location on our injector pump.

It looks inaccessible, but with a 15/16th spanner or shifter it should be possible to remove it.


The solenoid is on the right, with the top of the pump removed.

It shouldn't be necessary to go this far, I was replacing the throttle shaft seal when this photo was taken.

Friday, 12 August 2011

Electrical/Electronic Mods to our Oka

Being an electronics engineer it was inevitable that I would make and installed lots of electrical/electronic modifications and additions to our Oka.
None of these mods affect the basic functionality of the Oka, in fact there is only one essential electrical item which keeps the engine running or not, which is the fuel cut off solenoid on the injector pump.
As long as you can start the engine, the solenoid wire with 12v applied is the only electrical thing needed to keep it running. See this post for the minimum electrics to start and keep the engine running.
Electrical Mods to our Oka (** indicates my own design/construction)
Mods which relate to Driving
  • Smart alternator regulator for our 120A alternator (Sterling AR12VD)
  • Triple batteries with automatic charge connection and manual paralleling switches**
    • Supercharge Gold MF95D31R (760 CCA) starter battery
    • 2 x Supercharge MRV70 (105 AH, 760 CCA) Allrounder (Starting and Deep Cycle) house batteries
  • Solar panels (200W, 10 x 20W) and multiple battery charge controller**
  • Charge monitoring display system (current and voltage)**
  • Start Lock Out system**
    • Prevents the engine from being started until an enable button is pressed, after the ignition is turned on
    • Fitted with an emergency engine stop button
  • Reversing and forward facing (for seeing over crests) cameras and 9 inch LCD display
  • Wiper delay system**
    • 6 delay periods
    • 1 or 2 wipes per cycle
  • Dashboard electronics**
    • Voltage and charge current meters switchable to each battery (LCD and LED)
    • GPS PSU
    • Turbo Timer
    • Headlight/Step/Vent/Pump "Left On" reminder system
    • Laptop PSU for moving map system**
  • Remote central locking doors**
    • Fitted to all 3 doors, with interlocks so that any internal door handle can lock and unlock all doors**
  • Electric windows on both front doors**
  • Remote switching of fridge dc**
    • Allows fridge to be switched off from cabin when stopped (eg for fuel), to reduce battery load. Normally the fridge runs from 240v ac via the inverter while travelling as it's more efficient than dc, less cable losses. Solar panels provide power when the alternator is not charging
  • Automatic inhibit of Water Pumps**
    • Inhibits pumps when the ignition is ON, to prevent accidental pumping out of water if a pipe leaks or breaks while travelling
  • Diesel Transfer Pump to transfer fuel from rear to side tank
Mods which relate to the Motorhome
  • System switch functions for all rear electrical equipment**
    • Pumps, Lights, Fans
  • Water Level Meters for both main water tanks**
  • Fridge/freezer monitor and alarm system**
    • Display of fridge and freezer temps
    • Over temp and flame failure alarms
    • Indication of energy source (ac, dc or gas)
      •  Note: Fridge is normally powered from ac inverter while travelling, it's more efficient than powering from 12Vdc
  • Fridge Fan to circulate cold air, stops when door is opened**
  • Fridge LED Lights which operate when door is opened**
  • Window Fans to cool us at night (speed controlled from quiet breeze to gale force)**
  • 300W Sine Wave Inverter (Jaycar) with RCD (later removed since it couldn't handle the vibration)
  • Soldering Iron, 24v 60W, temperature controlled, runs from dc-dc converter**
  • Drill battery charger, 24v, microcomputer controlled
    • Runs from same dc-dc converter as soldering iron
  • Computer systems
    • GPS moving map system based on MacBook Air, USB GPS and Oziexplorer running under VirtualBox and XP
    • 17 inch LCD display mounted on engine cover
    • NextG Phone/Modem, (plugs into MacBook), with options of external whip and Yagi antennae
    • 2 x 40W channel HiFi system switchable from radio to computer**
  • Smoke Alarm inhibitor**
    • Prevents activation while cooking. Manual reset or automatic reset after 40 minutes
  • NiCd/NiMH Battery Charger (up to 10 AA and/or AAA batteries at once)
  • Rechargeable Dolphin LED Torch using 8 1/2 W LED's and 6v SLA battery**
  • Dustbuster converted to run from 12v (internal 12v to 6v switching converter)**
  • HF Radio, (Codan 7727 with VKS737 frequencies)
    • Modified to receive ABC and BBC shortwave broadcasts
    • Allows transmit/receive on the 40 meter (7 MHz) amateur band (call sign VK5MDR)**
    • Frequencies can be selected via an external VFO**
    • Allows broader range of emergency frequencies
    • Jenal SC2 microphone fitted to allow direct RFDS connection via Selcall though VKS bases**
    • Tapped whip and 9m Super Rod antennae
  • SW Battery Radio
  • LED Lights**
    • External LED camping lights
    • Internal LED lights
    • Automatic porch/step lights (comes on at dusk when door is opened)
  • Fridge dc low voltage cut off**
  • Roof Vent fan speed control**
  • Evaporative air conditioning controls**
    • Controls small evaporative a/c for use when the engine is off
    • Provides automatic shots of water to keep the evaporator pads damp instead of a continuous supply, to save water. Uses a timer to control a solenoid valve from the pressurised water supply
Future Planned Mods
  • Microcomputer controlled turn indicators/hazard flasher**
    • To accommodate variable loads with future LED lighting systems
    • Static or “Knight rider” type displays
    • Various Left/Right/Hazard “ringtones”
    • Auto volume control (louder with more ambient noise/radio on)
    • Brighter internal flasher LEDs
    • LED and wiring fault detection
    • Auto L/R reset after 15 sec (adjustable)
    • Warning sound, horn or silence on Hazard flasher
    • Hazard flasher can drive rotating lamp and/or alternating L/R or F/R indicators
    • Hazard can flash all lights (Headlights/Stop/Tail/Indicators) alternately to even out battery load
  • Air Conditioning controller**
    • To display internal and external temperatures
    • To control the fans, compressor and front/rear temperature balance

Where We Store Stuff in our Oka

We need to know where we've put things which are not used on a regular basis, like spares and tools, so I keep a list.
Also see this post for photos of other storage areas we've created around our Oka.

Black Hole Box
(This is above the cabin inside our raised roof. It's dark in there, hence the name)

            Engine spares (light weight) in plastic box
                        Fuel filter
                        Oil filter
                        Radiator repair stuff
                        Safety glasses
                        Thermostat and gaskets (2)
                        Water pump gasket
                        Welding glass
            Diesel pump (small electric water pump)
            Jumper leads (canvas bag)
            Kettle (dirty black campfire kettle)
            Screen room (pop up 2m x 2m x 2m insect proof tent)
            Snorkel and flippers
            Syphon (manual pump operation)

Front PVC Pole Pipe
(This is a 120mm diameter x 2m PVC pipe with screw caps mounted just behind the top of the front bullbar)

            Antenna poles (to extend the NextG Antenna height)
            Awning poles
            Earth stake
            Lengths of tube and strips of aluminium and timber
            Sand Flag pole (mounts on front bullbar in sand dune country. Also useful for hoisting a wire antenna 4m into the air)

Rear Compartment
(The rear compartment is inside the rear hatch, on the floor, but behind a bulkhead so things can't fly forwards in a sudden stop. It's used for heavier tools, equipments and spares)

            4 inch vice
            Air drill and grinding disks
            Heavy tools in steel toolbox
                        Breaker bar
                        Grease and grease gun (in sealed bag)
                        Large files
                        Large screw drivers
                        Large spanners/wrenches
                        Jack handle
                        Rubber hammer
                        Tyre levers
                        Wheel brace
            Hose clips
            Jerry cans for fuel, 1 or 2 (not often required, takes up too much space)
            Plastic box of spray chemicals
                        Brake cleaner
                        Silicone grease
            R pins
            Silicon, glue, gasket goo and Loctite
            Snatch strap and Equalisation strap (Winch/Tow Strap and Bow Shackles in external side box)
            Sockets (heavy)
            Spare nuts, bolts, washers and screws
            Square steel container (a 10L campfire oil drum) containing:
                        Brake fluid (1 l)
                        Diff oil (5 l)
                        Engine and transfer box oil (5 l)
                        Hydraulic oil (2 l)
            Suspension bushes/pins
            Welder rods and rod holder
            Gas blow torch

Rear Gate Tool Boxes
(These are boxes built into the skin of the rear gate hatch after removal of the internal steel panel)

            Allen keys
            Clamps, files, tie wraps, tent pegs and raw materials (Ali/Steel/Plastic) (LHS)
            Hex screw drivers
            Saws, chisels and cutting equipment (RHS)
            Small sockets and drivers
            Small spanners
                        A/F and Whitworth
            Bearing puller

Rear Overhead Compartment
(This is one of the internal overhead compartments built into the raised roof. Other compartments are used for domestic storage)

            Box of wire
            Coats, spare bedding and towels
            Electric terminal kit
            Electronic components
            Shortwave/spare HF Radio
            Spare insect door and window screens
            USB keyboard
            Yagi antenna beam (for NextG phone/modem)

Seat Compartment
(This is a long internal rear compartment built below a seat alongside our kitchen unit)

            Camping chairs
            Hessian sacks
            Hub lift adaptor and
            Sand mats
            Spade (small)
            Table top
            Table leg
            Wheel brace extension bar
            Torque wrench
            Wooden and plastic strips

Shower Recess
(When not used as a shower we store lightweight bulky things in it)

            Hanging rails for damp clothes
            Laundry equipment (line, pegs, soap, washing powder, washing up bowl, sponges, brushes)
            Water pump (electric bilge pump) with pipe and cable/plug
            Padded Milk Crate (used as a seat/step), containing
                         Wine casks
                         Laundry/dirty clothes bags
            Screens for all rear windows to provide heat and light insulation
                         Made from Aircell aluminium bubblepack insulation from Bunnings
                         Fitted with suction caps
            Spray water bottles for very hot weather
            Interlocking rubber mats
            Toilet tent

Side Box
(This is an external steel box mounted behind drivers wheel mudflap)

            Bow shackles (2 x 4.75 tonne)
            Winch extension strap (used as a tow/object removal rope)
            Ropes various

Under/Behind Drivers Seat

            Behind seat
                        Small steel toolbox with hand tools, pliers, small screw drivers, small wrench
                        Emergency Rucksack above toolbox
                        Flashlube and funnel
                        Rubber Gloves (for refuelling)

            In wheel arch box (seldom required items, accessible from under the seat, contents label on top)
                        Bearing locknut socket (4 pronged for Stage 8 Locknuts) and instruction card
                        Bearings (s/h, 1 of each type)
                        Brake pads (1 of each type)
                        Clutch cable (used, but usable for repair of cables)
                        Gas bottle to airline pipe (emergency tyre "air" source)
                        Hi Lift jack extension (for winching)
                        Hi Lift jack overhaul kit
                        Lift Pump and gasket
                        Spring repair kit
                                    (uses spare half leaf mounted under the rear body to repair broken spring eye)
                        Suspension pins and bushes
                        U-Bolt and nuts

Under/Behind Passenger Seat

            Behind seat
                        Airline (small), tyre pressure gauge and air blower tool (in canvas bag, behind seat)
                        Screens for the windscreen and front door windows (same type as for rear windows)
                        Tyre repair kit (behind passenger's seat, under library)

            In wheel arch box (seldom required items, accessible from under the seat, contents label on top)
                        Bearing lock washers and tab bending puller
                        Bearings (new)
                        Brake parts (wedges, springs, bleed nipples)
                        Free wheeling hubs spares
                        Gear ball joint
                        Oil seals
                        Spare  UJ
                        Spare steering rod ends
                        Split pins

Under Rear Bed/Seat
(This compartment is under the seat/bed base and shares its space with a 50 L flexible reserve water tank in a separate compartment)

            Drill bits, drill and battery
            Electrical tool kits
            Small hex screwdriver kit and small fixing screws
            Small Stanley socket set

On the Rear Gate
(The rear gate is for holding one of the spare wheels but we also use it for storing other external items)

            Coiled airline mounted on a 120mm diameter PVC pipe
                        (covered to avoid the effects of sunlight/ultraviolet)
            Levelling wedges
                        (no longer used as we have airbags all round, space for other items)
            Long handled spade (extension handle inside PVC pipe)
            Water hoses (long and short) coiled up inside the spare wheel
            Water tank/tap connectors (inside airline PVC pipe)
            Spare door key (well hidden)