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TPS problems

Posted: Fri May 30, 2008 9:35 am
by 99sidude
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.

Posted: Fri May 30, 2008 10:01 am
by Spunkster
It sounds like your TPS is out of adjustment. It should read .49volts at idle. You must first get the tps sensor physically adjusted as close to this as possible then you can use the software to fine tune the fully closed and fully open values in Parameters.

Posted: Sun Jun 01, 2008 3:40 pm
by 99sidude
That was it thanks for the help! I'm suprised my tuner couldn't figure that one out.