How the 4A-GE ECU works

[JMR_AW11]

phatBob Wrote:That is an outstanding piece of work.

I'm interested in acceleration enrichment at this time because its the last part of the fuel setup that I'm doing on a 20v engined AE86. I'm using the VEMS managment system which has configurable enrichment values based on throttle opening speed (although MAP based enrichment is also possible). I'd be very interested in any timing advance information that you may have come across, as a maximum I'm running 25 degrees advance and I'm sure it can use more than that.

Rob

Thanks to everyone for the compliments about the articles etc.

As for the ignition timing, I have worked out the relationship between the 8 bit value and the real timing advance. I keep meaning to update the graphs on my web page to show degrees BTDC.

If you could send me an old 20V ECU I could remove the MCU chip and read out the ROM code from the chip and post the factory ignition map on here if you like.

I've also successfully hacked into the newer ECUs like the 4A-GZE and 3SGTE which use a more advanced family of MCU. I'd imagine the 20V ECU will use one of these newer MCUs so I should be able to read out the ROM no problem.