Commodore V6 and V8 vehicles are fitted with with a diagnostic test light to alert the driver of electronic component failure associated with the engine management system. Marks 4WD Adaptors manufacture a diagnostic test light, switch and loom that can be fitted into any vehicle fitted with a Commodore V6 or V8 engine requiring simple and quick engine management diagnostics.

Vehicles previously fitted with carbie engines are commonly being re-powered with Commodore, Chevy, and Oldsmobile EFI V6 and V8 engines.  When the vehicle was fitted with a carburettor no problems were experienced as the carbie bowl acted as a reservoir and prevented fuel starvation. Unfortunately EFI engines rely on constant fuel pressure for the injectors to operate properly. In a lot of cases the fuel tanks are not equipped with baffles that prevent fuel starvation when accelerating quickly or climbing steep hills, the fuel supply line in some cases is also to small for the high volume high pressure pump.

To over come this problem Marks 4WD Adaptors manufacture a surge tank that is used in conjunction with a low pressure lift pump. The lift pump is mounted on the side of the surge tank, it transfers fuel into the surge tank which holds approximately 1ltr of fuel. When it's full, an over flow pipe caries the excess fuel back to the fuel tank.

A 12mm outlet is fitted in the top of the tank allowing unrestricted fuel supply to the high pressure fuel pump, the 12mm outlet is fitted with a pickup tube which is suspended approximately 25mm from the bottom of the surge tank. This allows heavy material and water to be separated from the fuel, a drain plug is fitted for ease of servicing. The return fuel from the engine is plumbed into the top of the surge tank through a separate fitting.

The tank is supplied with all fittings, lift pump, mounting bracket, hardware and instructions.

Marks 4WD Adaptors manufacture two types of replacement engine sumps that can be used in various conversion applications. The first one was designed for the 4WD Hilux but can also be used in 2WD Hilux with independent front suspension and other vehicles requiring track rod and suspension clearance. This diagram gives you the overall dimensions along this photo. Note: This is a front drop sump.

The second one was designed to fit the V6 into a Land Cruiser Bundera with a live front axle. This sump is a rear drop type and has been used in other vehicles such as Range Rovers.

The engine sumps are new and are supplied with a new oil pickup.

The Commodore engine does not have an engine driven cooling fan; the engine ECM/PCM controls an electric fan to maintain the engine temperature. Marks 4WD Adaptors now stock a cooling kit, which includes 2 electric fans, fan mounting bracket, top, and bottom radiator, hoses, hose clamps and fixing bolts.

The Commodore V6 engine is not normally fitted with an engine driven cooling fan; the engine ECM/PCM controls an electric fan to maintain the engine temperature. This system is normally satisfactory in most conditions however if the vehicle is to be used in sand or heavy off road conditions during the summer months requiring the air conditioning to be used then the electric fans will most likely not do the job and will cause the engine to over heat. For this reason Marks 4WD Adaptors have now manufactured two engine driven fan kits.

The first one is directly driven and consists of a new water pump pulley and an aluminium adaptor that bolts up to the 400mm diameter reverse direction fan the kit is also supplied with all bolts, washers and instructions.

The second engine driven fan kit utilises the original Toyota 22R viscous coupling and is supplied with a new water pump pulley, aluminium fan adaptor, reverse rotation fan (400mm diameter), bolts washers and instructions.

Note: The engine driven fan has been tested on our company Toyota Bundera with great success. The vehicle was used in the sand dunes near Robe, South Australia during the summer of 2001 in temperatures reaching the high 30’s with the air conditioning running flat out. At the time no fan shroud was used however, we have since found that for the air conditioning to work properly in heavy traffic where the engine is idling for long periods of time a fan shroud is required.  

Most Commodore V6 vehicles where fitted with automatic transmissions as a result few second hand engines are fitted with flywheels. However all of these engines fitted with automatic transmissions usually come with a flex plate which is fitted with the starter ring gear and engine balance weight. Marks 4WD Adaptors now manufacture a flywheel that bolts up behind the automatic flex plate thereby retaining the ring gear and the original engine balance.

These photos show one of our VS flywheels fitted to a flex plate. Photo 1, Photo 2.

When fitting the Commodore V6 to a manual transmission a manual starter motor must be used. The starter motor for the automatic can be identified as having a nose housing around the pinion gear. The manual starter motor is manufactured by Delco and only has the pinion gear protruding.

Marks 4WD Adaptors now manufacture manual starter motors. This manual starter motor has been designed to use the original automatic starter motor mounting bolts to secure it to the engine block.

These photos show Marks 4WD Adaptors manual starters and some automatic starters.

The standard petrol and diesel tachometer will not operate directly from the V6 ignition system. Marks 4WD Adaptors manufacture two interfaces for both petrol and diesel that will make operative original 4-cylinder tachometers by converting the pulses received from the V6 DFI module.

The wiring of an EFI engine can be a daunting task especially if you have no prior experience with electronics. well fear not because Marks 4WD Adaptors have an interface wiring loom which is fitted with the EFI, fan, A/C, fuel pump relays, and fusses along with the original GM plugs that correspond with the engine loom. The few remaining trailing wires are labelled to show you where to connect them.

For the Commodore ECM/PCM to function properly and allow the engines emissions to comply with EPA regulations it must acquire a speed signal from the VSS. Marks 4WD Adaptors manufacture a number of VSS units and VSS interfaces to suit most EFI engine and vehicle combinations.

Vehicles previously fitted with engines that ran on either Diesel or Leaded Petrol are required to have a ULP restrictor fitted to the filler neck of the fuel tank. A ULP restrictor from a later model or unleaded vehicle  can be purchased from your local wrecking yard and fitted to your vehicle.