Ok, i have a 2007 Toyota Corolla, turbo charged and using the FIC. Here is my problem, the car performs great high end, has a great idle, and all that, but when there is a load on the motor, and say your just cruising down the road and throw it in neutral, when the rpms fall back to idle, it goes past the idle point (about 800-900) rpm for my car, and dips to low, stalling out the car. Doesnt do it if you just rev the driveway or something, the car has to be moving, or load applied to the motor. I put the stock injectors in (260cc) and it works fine, with the fic, so i know its not an installation issue. I started with 550cc,no luck, and thought maybe 440cc would help, and thats what i have now, with the same prob. Does anyone have any tips on how to overcome this problem.

When you coast down in gear, the engine will pull a lot of vacuum and decelerate slowly depending on how hard you are pressing on the brakes. The stock ECU is usually cutting fuel during this time, the injector duty cycle will probably be 0% when you decelerate at medium engine speeds (2000-5000RPM) and very light loads (0-30kPa). Since there is no fuel being injected, the stock ECU will run in open loop mode at this time. When you press the clutch and/or shift to neutral, the RPMs will drop very quicly and the engine will pull less vacuum. Most stock ECUs will begin injecting fuel again around 1000-2000RPM and 25-40kPa, so it's important that your FIC's fuel table be tuned very well at these loads. Since the stock ECU is not usually injecting fuel when you are decelerating at high RPMs and very light loads, the car might not run any differently even if you have the "wrong" values in those cells of the FIC's fuel map.

Also, make sure you're not pulling timing at very low RPMs because that will make the engine likely to stall. We have seen at least one tuner do this, presumably to keep the idle smooth. Retarding the timing at 900RPM might not make the motor stall, but retarding timing at 600RPM will. Adjusting the FIC's fuel and timing tables in the lower couple of rows helped that car run much better.