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.
Information on the Toyota 4a-eg timing system - distributor driven.
http://www.autoshop101.com/forms/h23.pdf
Sensors
IAT Sensor
CLT Sensor
Timing
Here's a diagram of the type of trigger found in European and JDM Toyota 4A-EG engines.
In its simplest form we can use the G trigger and set VEMS as a Coil type ignition
Next step will be to modify the 24 tooth signal wheel to be 24-1, which will give us the ability to run fully sequential injection and coil on plug. The downside is that cranking may take longer (one rev!)
== Config - Coil type ==\n
# config using primary multitooth wheel only # still using distributor based ignition, or wasted spark ignition # depends on igchmax and h[2] table # CAMSYNC ##################################################################### cam_sync_f_edge_phase=FF cam_sync_r_edge_phase=FF reset_engphase_after=FF ## trigger and tooth wheel setup ################################################### # tooth wheel, angular width of tooth # For Toyota fitment we have a 24 tooth wheel revolving at 1/2 engine speed # Two teeth must be ground 180degrees apart 360 / 12 = 30 (0x1E) tooth_wheel_twidth1=1E # tooth wheel, angular width of missing tooth # 12 - 1 wheel, 2 times tooth_wheel_twidth1 = 60 degrees (0x3C) tooth_wheel_twidth2=3C tooth_wheel=0B # 11 teeth between the missing tooth # trigger1, bit0 0:falling/1:rising, bit1 0:toothwheel/1:coil, bit2 0:no filtering/1:filtering # Toyota G trigger: primary_trigger=FE primary_trigger=FE # trigger2, bit0 0:falling/1:rising, bit1 0:toothwheel/1:coil, bit2 0:no filtering/1:filtering #disable camsync use multitooth wheel on primairy trigger only secondary_trigger=02 # tooth wheel, active trigger tooth # after the missing tooth (00: right after missing tooth) # so that trigger tooth is ~60 degrees BTDC # Toyota with its 30 degree tooth width = 1 trigger_tooth=01 # The amount of degrees after the trigger till tdc ign_tdcdelay=3C # 60 degrees # you probably want 4 trigger event per cam rotation with the 2x 12-1 wheels you will have to trigger twice per # crank rotation, that what another trigger tooth is for, trigger again after 6 teeth (180 crank rot) another_trigger_tooth=6 crank_minper=50 # for std. coil tach signal ## Ignition setup # crank advance = 10 degrees ign_crank_advance=2E # EDIS:0x0? dummy: 0x7? disable:0xff bit0: invertout ign_out=70 # i assume it is a 4 cyl ? ignchmax=03
Config - Modified trigger type
Using a modified Ne Signal cam-wheel:
Using 24-1 over two revolutions we are able to provide COP and sequential injection. \n
# config using primary multitooth wheel only # still using distributor based ignition, or wasted spark ignition # depends on igchmax and h[2] table # CAMSYNC ##################################################################### cam_sync_f_edge_phase=FF cam_sync_r_edge_phase=FF reset_engphase_after=FF ## trigger and tooth wheel setup ################################################### # tooth wheel, angular width of tooth # For Toyota fitment we have a 24 tooth wheel revolving at 1/2 engine speed # Two teeth must be ground 180degrees apart 360 / 12 = 30 (0x1E) tooth_wheel_twidth1=1E # tooth wheel, angular width of missing tooth # 12 - 1 wheel, 2 times tooth_wheel_twidth1 = 60 degrees (0x3C) tooth_wheel_twidth2=3C tooth_wheel=0B # 11 teeth between the missing tooth # trigger1, bit0 0:falling/1:rising, bit1 0:toothwheel/1:coil, bit2 0:no filtering/1:filtering # Toyota modified Ne: primary_trigger=01 primary_trigger=01 # trigger2, bit0 0:falling/1:rising, bit1 0:toothwheel/1:coil, bit2 0:no filtering/1:filtering #disable camsync use multitooth wheel on primairy trigger only secondary_trigger=02 # tooth wheel, active trigger tooth # after the missing tooth (00: right after missing tooth) # so that trigger tooth is ~60 degrees BTDC # Toyota with its 30 degree tooth width = 1 trigger_tooth=01 # The amount of degrees after the trigger till tdc ign_tdcdelay=3C # 60 degrees # you probably want 4 trigger event per cam rotation with the 2x 12-1 wheels you will have to trigger twice per # crank rotation, that what another trigger tooth is for, trigger again after 6 teeth (180 crank rot) another_trigger_tooth=6 crank_minper=50 # for std. coil tach signal ## Ignition setup # crank advance = 10 degrees ign_crank_advance=2E # EDIS:0x0? dummy: 0x7? disable:0xff bit0: invertout ign_out=70 # i assume it is a 4 cyl ? ignchmax=03 # When setting up up timing # keep mda28 fixed at 10 degrees # then adjust ing_tdc_delay until the timing is at 10 degrees during cranking
Config Notes
When setting up up timing keep mda28 fixed at 10 degrees
Adjust ign_tdc_delay until the timing is at 10 degrees during cranking as verified by a timing light.
Later Trigger types
Toyota have developed sensors for their later engines (such as found on MembersPage/DanielHenriksson page). These use either a single tooth G trigger:
Or a twin tooth G trigger:
