How does the vacuum advance work (and why do I want that)?
How it works:
An engine under heavy load will ping/knock sooner (lean mixture) than an engine under a light load (rich mixture). If we give more pre-ignition to an engine under light load, the efficiency will increase and as a result the engine will use less fuel.
The vacuum in the intake manifold is a measure of the load on the engine. (full throttle up the mountain = throttle valve open –> very little negative pressure. Half throttle down the mountain = throttle valve partially closed –> a lot of negative pressure/vacuum). This means that if a vacuum is created in the intake manifold, we can advance the ignition slightly.
Why do you want this:
In summary, by using vacuum advance we can reduce fuel consumption in partial load, the combustion will be cleaner and the efficiency will improve.
As an extra for the more advanced technician:
Altitude compensation: The 123ignition uses absolute pressure, (MAP or Manifold Absolute Pressure) to adjust the ignition timing. This compensates for thinner air (lower air pressure) at higher altitudes. The oxygen concentration per volume of air decreases with altitude, which results in a richer fuel mixture that takes longer to ignite. In these conditions, more pre-ignition is needed for optimal combustion.
FAQs From Same Category
It is always possible to use your original HT-leads for the original look. Even when your engine has solid copper core cables it would work with a 123ignition. For the best performance we advise "carbon tension leads". These cables have a little resistance and very good isolation. Of course you can buy these leads at 123igntionshop.com. See here which sets we sell.
In some cases a very unstable boardnet voltage can cause misfires. The 123ignition is protected against high voltage peaks and goes in protection mode for a split second when a spike is detected. Most of the time this error occurs when the car battery is charged full again and the voltage regulator starts to work. This problem can be caused by a broken alternator / dynamo or bad voltage regulator. Unfortunately this is impossible to measure with just a standard voltage meter because we talk about high voltage spikes of micro seconds. You could easily test this to drive a while without working alternator / dynamo. Use a fully charged car battery and make sure no other important systems are driven by the dynamo belt, like the coolant pump!!!
The car battery has to put enough energy into the coil for a powerful spark. In the higher rpm range the time to do this is very short, so all conditions have to be perfect for good performance. Make sure you are using the right coil for your engine, see: "What kind of coil do you recommend?" Resistance somewhere in the primary circuit can cause a lot of ignition problems as well, think about the following: - Coil and ignition wiring: Use good connectors and cables of good quality - Ignition key: Make sure the dashboard ignition key is in good condition ( test to power the ignition/coil direct from the battery ) - Ground connection of the distributor: Make sure the distributor makes a good electrical connection with the engine.
Always use the spark plugs for your engine specified by the manufacturer of the car!