VehicleFitment/Toyota

The following resources have been obtained while installing VEMS on Toyota 4A-GE 16V & 20V engines.

VehicleFitment/Toyota/Injectors

VehicleFitment/Toyota/Triggers

VehicleFitment/Toyota/Sensors

VehicleFitment/Toyota/IdleAirController


After the previous work using pull-down resistors we moved onto the suggested 10k->12V pull-up resistors and the addition of a 220nF cap on top of C40.

Still not good, the latest trigger log shows some strange missing tooth issues:

http://www.vems.co.uk/VEMSTrigger/4AGETrigger3.txt

Action to try next:

  1. Try to match the OEM pull-up of 0.6V with smaller value resitors.
  2. Try pull-down resistors as before, but with LM1815 pin5 jumpered to cause LM1815 to ignore any voltage below 200-450mV
  3. Use a seperate ground feed direct to the LM1815 chip.

Toyota 24+4 Trace:

24+4.PNG

Recorded with USB Instruments Stingray

Config & Tables

http://www.vems.co.uk/VEMSTrigger/config.txt

http://www.vems.co.uk/VEMSTrigger/tables.txt

Connection Details

The Ne (24tooth) trigger is connected to Trig1, the G1 (4 tooth) trigger is connected to Trig2. The G- combined ground connects to the common grounds. Two 270Ohm resistors pull the signal down to ground.

Trigger Logs

Initial test:

http://www.vems.co.uk/VEMSTrigger/24+4InCarTrig.txt

Test with the Ne and G1 trigger inputs changed over Ge to primary trigger, Ne to secondary trigger - we were out of clues so we thought we'd try it...

http://www.vems.co.uk/VEMSTrigger/24+4AfterSwapTrig.txt

Changing back to the correct trigger connections but removing the pull-down resistors.

http://www.vems.co.uk/VEMSTrigger/24+4FinalMiseryTrig.txt

A log from the bench test

http://www.vems.co.uk/VEMSTrigger/24+4BenchLog.txt

The owner of the car has produced a spreadsheet to try and analyse the trigger logs:

http://www.vems.co.uk/VEMSTrigger/24+4waveformsgraphed.xls

Toyota 24+4 Distributor:

Ign6.jpg

#10 is the injector signal - indicating 1 injection event every two ignition events.

Divider=02 means injection event every second ignition event. Good if you have 2 injectors hardwired in parallel. (or, even than, you can (at the cost of a few wasted cycles) do something like: h[0]=00 02 00 01 .. .. .. ..