My tuner attempted to tune my car, but ran into problems with the TPS only starting to register more than 0% until 4000 rpm's. Basically it's impossoble to hold the motor between 2000 and 4000 rpm's because the engine repeatidly drops back to idle speed and surges back up even with constant throttle angle.
I took the tps off (its brand new by the way), and read its output using a constang 5v supply and an oscilliscope. According to that, the sensor is working perfectly through its range.
During the surging, the injector duty cycle continually goes from 0% to some normal sounding %.
Any idea what this could be? We confirmed no vacuum leaks. Could it be ignition related? Bad ecu? Any Ideas?
The setup is a jdm b18c-gsr with jrsc - 8 psi. Running 440cc injectors.
