How does an ignition distributor work?
As the engine rotates, the distributor shaft cam turns until the high point on the cam causes the breaker points to separate suddenly. Instantaneously, when the points open (separate) current flow stops through the primary windings of the ignition coil. This causes the magnetic field to collapse around the coil.
What should the distributor and spark plug lead orientation be?
At this point it is recommended that the HT lead orientation be checked. So with the rotor arm pointing approximately at 10 O’clock, this position indicates that the mating lead in the cap should be connected to No.1 spark plug lead. The direction of rotation for the distributor rotor arm is anti-clockwise.
Where does the firing order start on a spark plug?
The firing order starts at the distributor’s number one terminal and continues in clockwise or counterclockwise fashion until reaching the number one terminal again. If the manual gives the firing order as 1, 3, 2, 4 and the rotor moves clockwise, connect cylinder three to the distributor terminal immediately clockwise…
What causes the ignition timing to be different?
Any deviation away from the original standard engine specification, or where a dizzy from another source is used in the engine you have, the ignition timing will generally be different from that set by the manufacturer.
Where is the number one firing terminal on a distributor?
Look in the repair manual to locate the distributor’s number one firing terminal. Many distributor caps come manufactured with the number one terminal already marked. An alternative method is to point the distributor’s rotor to the number one terminal by manually turning the engine until the crankshaft and camshaft timing marks line up.
Where is the ignition coil on a HEI distributor?
HEI distributors contained the ignition coil in the top of the distributor cap. The HEI only needed 12V to operate. In the early 1970’s many manufacturers came out with a variety of distributor electronic ignition systems referred to as “DI”. An electronic module replaced the mechanical point style ignition contacts.
How does a GM high energy ignition system work?
A magnetic pickup (pickup coil) inside the distributor sensed the engine position, sent a signal to the module controlling the primary circuit and the rotor distributed the spark to the right cylinder. Some of the systems were: GM High energy Ignition System (HEI) – The HEI system used a coil built into the top of the distributor cap.
Where is the ignition module in a distributor?
Inside the distributor was the ignition module and pickup coil. Later versions separated the coil to a remote version and added a knock sensor with a timing module. Motorcraft (Ford) Duraspark – Ford and Lincoln Mercury products used a remote coil with the module on the side of the distributor.
How are spark plugs connected to the distributor?
With a distributor, the spark plug wires are connected to the top of the distributor cap in a circle. As the rotor inside the cap turns, it will point the contact to the different connections around the circle. The wires are connected to the cap in the engine firing order. A typical V8 GM firing order is “1-8-4-3-6-5-7-2”.