machurdler

I have a 95 240sx with an AEM intake. A week ago, i installed an SAFC2 because I plan on going turbo soon, set the settings to 0, and was on my way. I drove this way for about a week until today. I was pulling into a parking lot and once I pressed on the throttle, the engine started bogging out like it was running rich or something. When I tried to turn the car on it took around 10 seconds for it to crank and then it would run boggy once again and turn off. At idle, the rpms would go up and down from 0 -700 and then eventually turn off. I took the SAFC2 off, let it run like than, but the same sort of thing happened. So put it back on and let the car idle and adjusted the LO-throttle til there was a comfortable idle which was around 20%. I would push the throttle and the car would run fine, but when I let off the throttle, it would go back down to almost 0, flutter around the rpms again and then turn off. Any one have an idea of what's going on?