4A-EG Trigger
These have a potential market for Corolla (AE86 and newer) and MR2. These engines are used in Mk1&Mk2 Ford Escorts as they are the same as the Cosworth BDA engine.
Some decent scope traces.
two ways I would do it
1) use is in 'coil type trigger' mode any only use the G signal. Apparently this is not enough even for wasted spark (just distributor).
OR
2) grind off one of the teeth on on the 24 tooth wheel and run 24-1 and only use Ne signal
3) use both signals as is (Ne as primary trigger, G as secondary trigger), and make some firmware modifications
[PhatBob] What sort of modifications? I still cannot see how we'd know where 'home' is without a missing tooth pulse.
Sounds like a simple setup:
- LM1815 for primary trigger
- LM1815 for secondary trigger
This way we get a similar crank and crank-signal pulses to the processor as the HALL signal of the mazda-BP engine (eg. MembersPage/Fero ) has by default (without LM1815 of course).
Any info about the position of primary trigger falling edge ? If it's >50 crankdegrees BTDC, than it is supported without any firmware modification.
Information on the Toyota 4a-eg timing system - distributor driven.
http://www.autoshop101.com/forms/h23.pdf
Here's a diagram of the type of trigger found in European and JDM Toyota 4A-EG engines.
The signals are generated from the distributor, which means that the 24 tooth wheel runs at 1/2 engine speed. Therefore we'll have to grind 2 teeth off the Ne trigger 180 degrees apart.
The config entries for the trigger are:
[Insert config lines here]