i was trying to start up my motor for the fist time and had some trouble, first time trying this. turn the key and the engine turns over, no problem with starter. put the dizzy in and lined it up at #1 cylinder at 4 degees before TDC. then i put the voltmeter on the #1 wire and got no voltage? stuck the voltmeter into the tach outlet on the dizzy and got 12.6 volts, so i am getting juice to the dizzy, just doesnt seem to go to the terminal that goes to the spark plug wire. put the spark plug into the wire and rotated the dizzy back and forth with the plug grounded against the block and didnt get any spark? good ground between dizzy and block too, so i am at a loss?? i was hoping to fire this big ***** up but i must be doing something wrong? any help is greatly appreciated. thanks mike
dont mean to over simplify this, but have you checked the carbon ****on between rotor and cap? internal wiring cap to coil? i start with the little things first. then move to module and pick up coil. should be able to find ohm value for them on any gm website. good luck, bruce
it's a brand new dizzy. I don't know how they work. stoke volt meter in there and did get voltage inside though.....
Here ya go ! Mechanically timed ignition Distributor cap Most four-stroke engines have used a mechanically timed electrical ignition system. The heart of the system is the distributor. The distributor contains a rotating cam driven by the engine's drive, a set of breaker points, a condenser, a rotor and a distributor cap. External to the distributor is the ignition coil, the spark plugs and wires linking the distributor to the spark plugs and ignition coil. <SMALL>(see diagram Below)</SMALL> The system is powered by a lead-acid battery, which is charged by the car's electrical system using a dynamo or alternator. The engine operates contact breaker points, which interrupt the current to an induction coil (known as the ignition coil). The ignition coil consists of two transformer windings sharing a common magnetic core—the primary and secondary windings. An alternating current in the primary induces alternating magnetic field in the coil's core. Because the ignition coil's secondary has far more windings than the primary, the coil is a step-up transformer which induces a much higher voltage across the secondary windings. For an ignition coil, one end of windings of both the primary and secondary are connected together. This common point is connected to the battery (usually through a current-limiting ballast resistor). The other end of the primary is connected to the points within the distributor. The other end of the secondary is connected, via the distributor cap and rotor, to the spark plugs. Ignition Circuit Diagram - Mechanically Timed Ignition The ignition firing sequence begins with the points (or contact breaker) closed. A steady charge flows from the battery, through the current-limiting resistor, through the coil primary, across the closed breaker points and finally back to the battery. This steady current produces a magnetic field within the coil's core. This magnetic field forms the energy reservoir that will be used to drive the ignition spark. As the engine turns, so does the cam inside the distributor. The points ride on the cam so that as the engine turns and reaches the top of the engine's compression cycle, a high point in the cam causes the breaker points to open. This breaks the primary winding's circuit and abruptly stops the current through the breaker points. Without the steady current through the points, the magnetic field generated in the coil immediately and rapidly collapses. This change in the magnetic field induces a high voltage in the coil's secondary windings. At the same time, current exits the coil's primary winding and begins to charge up the capacitor ("condenser") that lies across the now-open breaker points. This capacitor and the coil’s primary windings form an oscillating LC circuit. This LC circuit produces a damped, oscillating current which bounces energy between the capacitor’s electric field and the ignition coil’s magnetic field. The oscillating current in the coil’s primary, which produces an oscillating magnetic field in the coil, extends the high voltage pulse at the output of the secondary windings. This high voltage thus continues beyond the time of the initial field collapse pulse. The oscillation continues until the circuit’s energy is consumed. The ignition coil's secondary windings are connected to the distributor cap. A turning rotor, located on top of the breaker cam within the distributor cap, sequentially connects the coil's secondary windings to one of the several wires leading to each cylinder's spark plug. The extremely high voltage from the coil's secondary -– often higher than 1000 volts—causes a spark to form across the gap of the spark plug. This, in turn, ignites the compressed air-fuel mixture within the engine. It is the creation of this spark which consumes the energy that was stored in the ignition coil’s magnetic field. High performance engines with eight or more cylinders that operate at high r.p.m. (such as those used in motor racing) demand both a higher rate of spark and a higher spark energy than the simple ignition circuit can provide. This problem is overcome by using either of these adaptations: Two complete sets of coils, breakers and condensers can be provided - one set for each half of the engine, which is typically arranged in V-8 or V-12 configuration. Although the two ignition system halves are electrically independent, they typically share a single distributor which in this case contains two breakers driven by the rotating cam, and a rotor with two isolated conducting planes for the two high voltage inputs. A single breaker driven by a cam and a return spring is limited in spark rate by the onset of contact bounce or float at high rpm. This limit can be overcome by subs***uting for the breaker a pair of breakers that are connected electrically in series but spaced on opposite sides of the cam so they are driven out of phase. Each breaker then switches at half the rate of a single breaker and the "dwell" time for current buildup in the coil is maximized since it is shared between the breakers. The Lamborghini V-12 engine has both these adaptations and therefore uses two ignition coils and a single distributor that contains 4 contact breakers. A distributor-based system is not greatly different from a magneto system except that more separate elements are involved. There are also advantages to this arrangement. For example, the position of the contact breaker points relative to the engine angle can be changed a small amount dynamically, allowing the ignition timing to be automatically advanced with increasing revolutions per minute (RPM) and/or increased manifold vacuum, giving better efficiency and performance. However it is necessary to check periodically the maximum opening gap of the breaker(s), using a feeler gauge, since this mechanical adjustment affects the "dwell" time during which the coil charges, and breakers should be re-dressed or replaced when they have become pitted by electric arcing. This system was used almost universally until the late 1970s, when electronic ignition systems started to appear. [edit] Electronic
You are not turning the HEI dist quick enough to make it spark.Hei does not have points to break to cause the spark.Jimmie King
Well alrighty then, guess I shoulda just fired it up. I will try it again soon. Thanks for the straight answer. Also thanks for the above info. Mike
It probably got pissed off because you referred to it as a ******** "dizzy" instead of it's proper name "distributor". I've been working on these things for 50 years and I have never heard of the method you allegedly used to check for spark before either. Where did you come up with that method?
I just figured it should spark with juice to the distributor and lined up at cylinder inumber 1 and ground the plug on the block. I never did this before. how am I supposed to do it? what is the procedure? thanks sorry I called it a dizzy Typing on this phone sux....
Just so you know, there is a gap between the tip of the rotor, and the terminal in the distributor cap. The spark jumps it when the engine is running, but you'll never get voltage out of it measuring it static.
thanks for all the help. i guess i was thinking too much here. turned the key and the big ol ***** fired right up. ran it for 20 minutes with no problems.
The Jalopy Journal
