So. Being my first project on arduino and being s car guy I decided that 400-900 was too much for efi and I had an Arduino layin around I decided to think about how to add more fuel to my stroker motor. I can hear it ping on the low end when I step on it ( it's a jeep 4.0 with head work, stroker crank, 60 overbore with the h260 from crane cams) and was wanting advice/ help on how to make this happen. I was thinking induction sending off the number 1 injector and multiplying by 2 to get rpm. And using rpm and tps to add fuel while using integer variables to edit the fuel table so it's adjustable. Any ideas are welcome to be herd and thanks to anyone who can help.
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So after spending all this money on your engine you are going to try doing it with an Arduino and risk hurting it?
This would be a pretty daunting task for an experienced coder, which I am assuming you are not.
Just spring for a Megasquirt and never look back.
It's possible - Powercommanders do exactly this. If your batch injected you might have only two injector banks to tweak. If it's full sequential you might have to do all 8 injectors seperately.
It won't be easy to do without a disposable motor/ECU and an engine dyno.
I'm rather inexperienced with code but did have a robotics unit in highschool that we just finished using robot c and I beleve C++. As for the efi, I'm not thinking a full, standalone efi, but something to drive 2 extra enjectors at the Tb to richen up the fuel mixture and change the voltage feedback of the O2 sensor to not see the extra fuel so the factory efi will never know there's any extra. So what I'm looking at is a driver for 2 injectors, an rpm sence to time/ control Duty cycle if the injectors, and an O2 sensor emulator. The O2 is 0-1V. The rpm sence is still being decided. The 2 injectors are 12v and I will need to find a power switching method due to the amperage draw of them. Thanks everybody for the input. And trewjohn, it's a stright 6 that I wanna add 2 injectors just under the TB and control independently.
When it's running closed loop you shouldn't need to adjust mixture to fool the 02 sensor as its auto correcting.
Are you sure the problem is not ignition related? Have you got a wideband sensor and some readings? A crude way some people use to richer is to bump up the fuel pressure.
Did it "ping" before the head work? Perhaps your compression is too high? Might try some racing fuel to see if that stops the pinging. I agree with trewjohn2001, sounds more like an ignition problem.
I can't adjust fuel pressure without a changing the pump as the regulator is on the pump in the tank. I checked the timing with a gun and every other gear head I talk to agrees with me that it's a safe timing. I can briefly watch the fuel mixture on the obd port and it's all over the place and is usuly lean. It gets kinda safe at 2000 rpm and less than 25 % throttle but is lean up past 2500. Also, the ecu has called a code from this as a generic O2 fault and keeps coming back. I'm going to try this and hope one of the side effects is that it helps the O2 readings and clears the cel code. It's only 9.1:1 compression and the only head work we did was port and polish and I beleve bigger valves. No decking the head or block.