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Hi, this is actually my first time tuning an itb car for a daily driven street use car. I found that there is a lean spot when there is a huge increase of throttle opening. And at low load or cruise, the air fuel ratio will become very rich. Do i really need to use a map sensor to compensate for this problem?
The throttle increment for the table is 0,2,5,7,10,15,20,30,40,60,80,100
the ecu used for this application is link g4+ xtreme
I haven't tuned a car using Alpha-N, so I may be mistaken. However, can you not just use a throttle enrichment (tip in...etc) compensation map to add more fuel depending on the rate of change of your throttle opening?
Assuming it is an NA engine you shouldnt need a MAP sensor connected. For accel enrichment you typically need lots more sensitivity and a bit more clamp than a single throttle engine. I will post some example settings from one of the ITB engines that I work on (typically set your hold to the number of cylinders if running sequential, this example came from a 6 cyl engine).
I'm running a B20/vtec motor with ITB's as a daily with an ECU that's quite limiting. From what I have noticed is that at small openings the tps tip-in doesn't engage so I'm running at about 1.03 to 1.08 lambda with steady lambda at 1! What I noticed during my tuning period with this car is that if i targeted a little bit reacher mixtures .98-.96 all the hesitation that I have at lambda 1 goes away! I will say it again my ECU is limited and I can only adjust how much fuel to put in when the tps tip-in kicks in not when it will kick in.
Adam with this kind of small percentage on Accl. dead-band wouldn't give erratic use if the TPS fails or if there is a little bit of play between the TPS and the throttle actuator? I had a TPS failure before that's why I noticed that!
Just found out that link g4+ have an option called open loop lambda table for itb tuning. Already fitted a vacuum chamber and a map sensor. Set it up as Load = map , and fuel axis = tps , and the ecu will compensate the load fuel demand automatically. This is brilliant. And the car is running really smooth.