MembersPage/PhatBob/ToyotaFitting (2015-01-01 07:00:00)

The Toyota/Lexus COPs are still causing me problems. They kill 7.5Amp fuses and have hurt two IGBTs.

I cannot seem to get a change in the ignition advance when changing the spark map. And the same seems to be the case with the VE table, theres not any change in AFR when adjusting the map values and burning the table.

I'm clearly doing somethings wrong,,,

The car:

Simon86.jpg

Toyota Corolla AE86

The engine:

20VToyota.jpg

A 20V 4A series engine

The CAS:

RawEngineeringCASKit.jpg

RawEngineering4ACAS.jpg

Coil On Plug

The customer 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.

copsFitted.jpg

We have a Toyota workshop schematic for the COP:

ignSchematic.jpg

  1. +12V
  2. Ignition Fired (IGF) - signals to ECU that spark has occured
  3. Ignition trigger (IGT) - triggered by ECU
  4. 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.

sparkingPlug.jpg

It has been suggested that the following circuit be used to enable us to keep the IGBTs and to not overload the 74HC259D.

ToyotaCOPCircuit.png

The 'test bench':

sparkTestBench.jpg

[MembersPage/PhatBob]Not at any RPM, voltages were applied to the IGT pin as spark occured and the current read, the DVM was not able to read the rate of change.
  • This was read by connecting the 7V supply to the IGT pin (for a short instance? or continuously?)
[MembersPage/PhatBob]Short instances and continuously.

sparkedByVEMS.jpg

' try just a 649ohm to vbatt I think that will work just fine and save 1/2 the work'

' I would also say put it in the box not in the wires'


Old stuff:

Progress, the loom is 75% built, and the injectors are connected.

Using the stock ignition system, I was able to get the car to run for a few revolutions and then it stopped. I changed the cranking threshold to 1000rpm and the engine ran for a few seconds.

[PhatBob]I realise this, I was simply trying to remove MAP from the equation, as it stands this engine will not use AlphaN.

[Marcell]This is when it's time to start tuning. Just give the engine air and tune fuel (and ignadv as necessary). First it's enough to just hack (playing with afterstart, req_fuel, warmup and alike; nothing will be perfect at this stage) as much as to let it idle long enough to warm up, because VE table needs to be tuned when warm. Than (starting again with cold engine) you must go back to warmup and than finally afterstart.

If VE does not change pulsewidth / behaviour at low MAP, maybe you have already added too much fuel with injopen (use injopen=00), battfac or injocfuel.

[PhatBob]Thanks. The reason for it stalling after starting was because when the cranking threshold was reached the fuelcut_min_kpa value was read and found to be FF. Changing cranking threshold to 3000 allowed it to tick over, but it would cut the engine at 3000rpm.

After setting fuelcut_min_kpa to 00 the problem still persisted, Dave suggested changing the Decel Fuel Cut and overrun fuel cut values, and the engine was then able to run with a cranking threshold of 300 again and rev to 3500rpm.

[Config file]

[Tables file]

[Datalog for a running session]