Distributorless Glanza
This device replace the stnadard distibutor and allows the use of four or too coils which fire the plugs directly. It also indicates the ignition timing the is being sent by the ECU. This is useful for tuning piggy back ECU system. With a piggy back system the actual timing is not known.This is complicated more by alterations to the map signal. Many a broken ring lands can be attributed to wrong ingniton timing
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The distributor of a starlet contains three sensors. G1 ,G2 and Ne. The Ne sensor has 24 tooth. These tooth represent 30 degrees crank rotation. G1 and G2 are 360 degrees apart. The first Ne after a G1 is 10BTDC on the compression stroke of cylinder one.Based on this information it is possible to calculate the ignition timing based on an IGT signal . The IGt signal can also be channeld to one of four output and hence the distributor arm is nolonger required.
This is the finished schematic for the ingition monitor and distributorless Ignition system. The next step is the manufacture of the printed circuit board.
The operation is quite simple. All of the signals from the distributor are cleaned up.When a G1 signal is recieved an interrupt to the microcontroller occurs. The G1 signal starts a counter A .When a G2 signal is recieved the another interrupt occurs. The microcontroller then reads the count on the counter.An IGT signal starts another counter. Remmeber Igt is the signal which fires the coil. An interrupt occurs on the first ne after a G1. This is 10btdc. The controller reads the count at this point. The ignition timing is therefore = a/b * 360 + 10 btdc
What is the igniton timing of a starlet? 1,3,4,2. We know that The first Ne after g1 is 10btdc on cylinder 1. So what cylinder will fire next? So we prepare for the firing of cylinder 3. We basically have four outputs and with elcetronic logic(gates) we can channel the output to the appropriate gate. So instead of the dizzy on the distributor we have four output ports for four coils
This is the printed circuit now being populated with components
