Latest
Running on a single coil using the stock distributor now.
Engine starts nicely even at 0 degrees.
Currently looking at control of IAC (see section below)
The car:
Toyota Corolla AE86
The engine:
A 20V 4A series engine
The CAS:
Idle Air Controller
The IAC has a two 20Ohm coils centrally fed with +12V, grounding one coil causes engine speed to drop as the IAC is closed, the other causes engine speed to rise as the IAC is opened. With no connection the IAC remains 50% open.
I think that the stepper motor controller would have to be used to control the coils.
This is implemented, and works fairly well: MembersPage/GergelyLezsak/IdleControl , but not yet merged to stable.
Coil On Plug
Simon would ideally like to use Toyota COPs for the installation. These plugs have a built in igniter circuit. These fit very nicely on the engine. And would make the installation look neat and professional.
We have a Toyota workshop schematic for the COP:
- +12V
- Ignition Fired (IGF) - signals to ECU that spark has occured
- Ignition trigger (IGT) - triggered by ECU
- Ground
Tests
Initially using two 1K resistors as a potential divider to provide a trigger voltage to IGT (measured @7V) we got a good spark.
Using a 7805 to regulate the trigger voltage to 5V.
Current through my DVM shows 13.99mA.
With a 1K resistor in the way it draws 3.xxmA but does not fire.
With a 500Ohm resistor it draws 5.56mA and sparks.
It has been suggested that the following circuit be used to enable us to keep the IGBTs and to not overload the 74HC259D.
The 'test bench':
- The resulting (continuously repeating) spark with [IGT] at ~7V drawing ~7mA
- what RPM was it ? (or how many sparks/sec?) I assume the 7mA was a mean value, so we need to know frequency to calculate energy / spark
- This was read by connecting the 7V supply to the IGT pin (for a short instance? or continuously?)
