MembersPage/DanielHenriksson

Toyota Celica GT-Four -88 install


I'm installing a Genboard 3.2 in my Toyota.

The engine is a 3SGTE 4 cyl turbo.

I've sorted most of the board configuration, WBO2, EGT etc.

Now i've started thinking about the trigger options.

The engine has 2 trigger wheels with 3 VR sensors mounted in the distributor.

One wheel with a single tooth and 2 VR mounted 180 degs apart

Another wheel with 24 tooths even spaced (every 30 crankdegrees), no missing tooth

The distributor is adjustable, atleast +-10 degs.

This is the so-called 24+1 trigger that is also used on some nissan. See VehicleFitment/Nissan . Working well with released 1.1.x (1.1.18 at the moment but 1.1.22 should work just as well. Don't use 1.1.23 unless for auditrigger).

Multitooth option

Coil type option

Connecting the LM1815 outputs is safe (open collector), but the LM1815 output we use is stupidly designed to be pulled to low most of the time, and only released (to the 5.6k pullup resistor) when the pulse comes (input passes 0 and falling). Check the LM1815 datasheet, there might be another output that we normally not use. Or diodes can be used to act gates.

At worst, some firmware mod is probably needed (or more HW hacking).


Here is a link with pictures of the wheel and VR sensor arrangement.

[PDF with pic.]

(Borrowed the link from EmilLarsson?, hope you don't mind.)

The question is then what does it take to make this work with the Genboard?

[ MembersPage/PhatBob ] This is a later version of the trigger arangement that I'm trying to get running on VehicleFitment/Toyota The simplest bet seems to be a modified trigger.


Some general trigger questions - updated 2005-05-21


Ignition events are scheduled from the trigger_tooth + N * another_trigger_tooth.

AdvancedIgnition that uses the last tooth possible is coming (a bit stalled). Feel free to join development.

The scheme used above is very critical to cranking/starting advance acurracy, especially on a high-comp, low-inertia engine with drained battery. The crank speed varies very much during each revolution, if the sampling used for timerticks/crankdeg is done far away (in crankdegs) from the actual spark event, or if the sampling is done on a per/rev basis you end up with very bad acurracy. Maybe the problems described on Jose's page MembersPage/JoseLCortes/FullySequencial is somewhat related to varying crankspeed during cranking, in his case it messes up the trigger state-machine?


Some notes about supply noise


I solved the problem with decoupling caps but maybe there is something i've missed in the documentation?

(The docs aren't exactly for dummies... :-) )

There is an L4 and some decoupling caps for the EGT power that should. Can you identify if noise is in the GND or in the +supply?