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  Here is another engine conversion that I did when I had my workshop. Not quite as interesting or challenging as the Celica conversion, but a nice end product that’s for sure. The vehicle is a 1993 Toyota Hilux 4×4. Originally fitted with a 2.8 litre diesel engine and five speed manual transmission, it was bought for the right price as it had overheated and cracked the cylinder head. The cylinder head had been removed and the bores were very rusty from sitting around for so long. To repair the diesel engine would have cost around $5000.00 and the old 2.8 was never a powerhouse, usually very reliable but performance was a bit lacking. So we decided on fitting a 3.8 litre Buick V6 engine from a 1990 Holden Commodore. The cost of the engine and the bits and pieces needed for the conversion was around $1500.00 less than the diesel rebuild and the difference in power is incredible.

  Luckily people have been doing these conversions for a while now and all the bits and pieces needed for the change are available over the counter from a couple of firms. We chose Marks 4×4 as they had everything we needed in kit form. So out came what was left of the diesel engine. The original gearbox was retained, with a change of bellhousing and clutch plates and slave cylinder. The passengers side original engine mount had to be cut off the chassis rail and the new one welded to it. Because this vehicle has independant front suspension the steering damper had to be relocated, one bolt on bracket and one welded bracket needed there. Then it was time to fit the engine and bolt everything up. As you can see it looks like it belongs in there! The next thing was to wire it all and install the computer inside, behind the passengers kick-panel. The fuel system had to have a bit of work, running high pressure lines to and from the engine, fitting a high pressure pump inline and fitting a surge tank. We had some custom hoses made up to mate the Holden power steering pump and A/C compressor to the Toyota units and adapted the air intake to the original Toyota filter. The original radiator was used with an adaptor to mate the bottom hoses together and an electric cooling fan was fitted. The exhaust system uses the original Holden manifolds with a custom set up back from there.

  What we ended up with was a totally different vehicle to drive. The difference in acceleration alone was great, and it didn’t matter what gear you were in it would still pull like a steam train. Even though the diesel engines are super reliable and still get you where you need to go, this conversion has made this Hilux very pleasurable to drive. It has even shocked a few people who think they can blow it into the weeds because it has diesel bagdes on the back! Have to take those badges off it one day, naah let’s leave them on, it adds to the fun! Take care and be safe on the roads.

Craig

  EFI or electronic fuel injection has been with us for quite a while now and has proven to be far superior to the old carburettor. The easiest way to describe how it works is that inputs recieved from various sensors around the engine (and sometimes transmission) send a signal to the ECU or electronic control unit, the control unit processes these signals and sends an output to the fuel injectors, air bypass valve and on distributor-less engines, the coils. Lets take a brief look at the input, output and control unit functions of a common multi-point type injection system used on most main-stream cars today. To simplify this post ( and not bore the hell out of everyone ) we will leave the ‘hardware’ side of things to another day.

  Most input or information sensors are resistors that modify the voltage applied to them by the computer, this voltage is called the Reference Voltage. The computer sends this reference voltage to the sensor and as the resistance in the sensor changes so does the return voltage to the computer. The ECU or computer then uses these changes in voltage to make the necessary adjustments to keep the engine running at it’s best. Typical input sensors found on todays vehicle will include;

• Airflow meter - placed in the air intake tract and used to measure the amount of airflow and adjust the fuel delivery appropriately.
• Manifold Pressure Sensor - often referred to as MAP sensors and used in place of air flow meters to determine the load on the engine and the fuel required to keep it running.
• Air and Coolant temp. sensors - used to provide a rich air/fuel mixture for starting and warm-up and to measure air density which affects air/fuel ratio.
• Oxygen sensor - regarded as the most important information sensor. Located in the exhaust pipe or manifold. Used to measure the amount of oxygen in the exhaust gasses, an indication of whether the engine is running lean or rich.
• Throttle Position Sensor - tells the computer whether the engine is at idle or wide open throttle or any position in between. Once again used to calculate the amount of fuel required.

  The ECU or computer is the brain that processes these voltage signals and adjusts the outputs in accordance with it’s program or ‘map’.

Typical outputs are;

• Fuel Injectors - the principal component in the output system. The computer reads from the input sensors and calculates when the injector should open and for how long to maintain the ideal air/fuel ratio.
• Air bypass valve - used to correct idle speed and air/fuel mixture at idle. Allows air to bypass the closed throttle body butterfly.
• Coils - on a distributor-less ignition the computer is used to ‘fire’ coils that are located either on top of the spark plug (via an insulator) or close by with a small plug lead. The instant the coils are fired can be dependant on engine speed and load.

  That sums up our brief look into the EFI system. Obviously this is only a basic overview of things, but my idea was to give you an understanding of how and why it works. And besides, I could write a whole book once we get into the nitty-gritty of it all!

Take care and be safe on the roads.

Craig

  I recently had the joy (ha ha) of helping a friend diagnose a problem with his Mitsubishi Pajero. I suppose you couldn’t even call this vehicle modern as it was a 1993 model. I hate to think what problems a 2007 model will cause down the track! The problem we had was with the ‘Super Select’ system, which when working allows you to select four wheel drive on the ‘run’. A great system no doubt, but not something you would want to stop working halfway through a drive to the ‘back of Bourke’ (a long way from civilisation for those outside Oz!) The system has five earthing switches on the transfer case and gearbox, a small control module, two vacuum switches in the engine bay and a vacuum operated gizmo (the technical term!) to engage the front hubs. That to me spells trouble in itself, a complicated system on a vehicle that is designed to take you places you normally wouldn’t go with a conventional car.

  The first issue was the green lights on the dash flashing, indicating that the hubs where trying to lock in even though the transfer lever was in two wheel drive. We tracked that down to the ‘gizmo’ on the front differential housing had vacuum to only one side of it’s diaphragm. To keep the hubs in the unlocked position it needs a vacuum supply to both sides. O.K. so once we swapped the vacuum hoses around and provided vacuum to the other side the actuator and the hubs retreated into unlocked position and the lights on the dash went out. Yee-hah. So now we had to work out why the vacuum had disappeared on one side only. We checked vacuum supply to both solenoids, checked vacuum hoses for splits or damage and checked power and earth supply to the solenoids. All good, except for the earth supply for the solenoids wasn’t great, but we reasoned if that was the cause then both solenoids would be playing up as they are wired in series. Checking the solenoid’s resistance revealed a huge difference in the two. Problem one, need to replace solenoids.

  I was still concerned by the quality of the earth provided to the solenoids. Probably not causing too much drama but just not right. We found that by using a test light connected to the positive terminal of the battery and the probe stuck into the negative side of the solenoid connection, that when we earthed the wire at the gearbox switches the earth improved drastically. Why were the switches on the gearbox and transfer case not giving a good earth? Only way to find out was to pull them out. Luckily we were doing this in a garage and not on the side of the road, bit of a mission! There was two switches that our earth wire was joined to, one on the gearbox and the other on the transfer. When we unsrewed these we found that someone had obviously tried to fix this problem previously. Where the wire goes into the switch there was lucky to be two strands of the wire left! Because the wire comes out of the side of the switch, not the top, as you screw them out if you are not careful the wire twists around itself and breaks. Luckily we were able to solder another piece of wire to what was left coming out of the switch. Another problem we found was that the switches themselves had a reasonable amount of oil inside them, not good for providing an earth. So we cleaned them out as best we could, carefully re-installed them and now we had the test light glowing like a champion. Problem two, near broken wires and switches full of oil.

  We ordered new solenoids from Mitsubishi, they only come as a pair even though we only need one! Just shy of $200.00 which I think is reasonable. We have just fitted them today and it all works like a charm. Problem solved. Looking at four wheel drive forums and web pages, it seems this problem is very common with Pajeros. For my dollars I’d much rather have the slight inconvenience of getting out of the vehicle and manually locking the hubs in, rather than relying on electronics to do it for me. You don’t want to be second-guessing when it comes to driving in difficult terrain. A brilliant idea no doubt about that, but poor execution.

Take Care and be safe on the roads.

Craig