When wiring up a car, or wiring in an ECU, one of the most important aspects, is good wiring.

Now, everyone thinks of wiring as being a good 12V power supply - "I must have a good 12V. I've run really thick battery leads". It's not the only thing.

There are two sources to power supply. You've got a ground, and you've got power.

Let's take an injector for instance. That has power, and it has ground to operate it. An ECU will ground the pin of the injector to open it.When modifying a vehicle, one aspect that should be taken into account is your cooling system.

If you take an example of a 1971 model car, with a 2000 model fuel injected engine. You can put a 2000 model radiator and thermofans into the engine bay. One thing to consider is that you will have dual thermofans. One on the left, and one on the right of the radiator.

You will wont to turn one thermofan on at a time, just above operating temperature, and the second thermofan should come on around 4 to 5 degrees after that. This saves electrical load on the battery and charging system. You are not turning on 2 thermofans at once. And this also lets you turn on the second thermofan when the air conditioning compressor is turned on.

Something else to keep in mind is, if you have an air conditioning condenser sitting in front of the radiator you are restricting air flow passed the radiator. But then, if you have an intercooler of some kind in front of that, you're restricting air flow passed both the air conditioning condenser, and through the radiator.

So, alway keep this in mind, and try to keep the airways clear and allow air to pass through radiators and intercoolers for maximum efficiency.

One last thing to keep in mind with cooling systems, is that you are going to want to dyno tune your car, you will want to get the maximum out of it. Make sure all of the pipes and hoseclamps are up to scratch, and there is not something that is second hand that is going to blow out or fly apart when it's on the chassis dyno.

If you are wide open throttle running down the drag strip, and you have a bad ground supply to the ECU, then that will have a bad ground supply to the injector. That can lead to leaning an engine out, and even causing an engine blow up.

To ensure this doesn't happen, you need to make sure all of the ground points on your engine are in really good condition and good spots.

On and OEM factory car, they often have about 4 different ground points. They have one at the front of the engine, one at the back of the engine, they generally have one down on the side of the motor, and one that goes from the alternator bracket to the battery.

These are all critical to the way an engine runs. Whether it's to ground injectors, or ignition coils that need to be grounded to give good spark, once again, if you don't have good ground for your ignition system, you're not going to have a good spark, it's going to break down under load when the engine is trying to produce maximum power.