ChrisT88

I have been thinking about the differences between the older ECU in my Supra that seemed to run incredible with high HP and a piggy back while the newer ECU in my GS300 suffers from what I can tell is a constant updating of the fuel map from the ECU in an attempt to find a happy sensor input value from various sensors(I would be very interested if anyone could tell me what all of these sensors are). Jeff Tai said in a post that he thought the issue was that the newer GS300 ECU has over 25 different fuel (and I assume timing) maps available. This seems to coincide with what I have experienced when simply unplugging my O2's in an attempt to run "open loop" which does not work, but may have prolonged each maps use before changing.

Now my question is, what if I were to take the average injectors pulse ranges high and low and map it linearly to the throttle peddle signal(hi/lo calibrated at install, idle RPM?) and "simulate" to my FIC INJECTOR_IN wires on the FIC?

Since I do not understand how a modern ECU works I admit this may have have a flawed approach but if there are any other circumstances such as idle RPM, sensors that need consideration when outputting an RPM to the motor they too may be easily incorporated or simulated to solve our issue with the simpler tuning equipment.

ChrisT88

No speculation on this?

JeffTsai

iTrader: (1)

That's the beauty of the FIC. It can simulate the signals to keep the stock ecu happy. Just modify the injector pulse. It's completely different from a SAFC where it just modifies the MAF signal. The FIC keeps the MAF signal unmodified(or you can change it a tiny bit) and you can add or trim the fuel injector pulse directly. The stock ecu has no feedback circuit for the injector pulse so it won't throw a code if you're compensating for boost or bigger injectors. There's also the O2 feedback skew function that you use to keep the ECU happy while under boost.