rujoesmith

98 civic ex, d16y8, MT, 150k

I've been having problems with this since I replaced my head with a re-manufactured one. When I lightly depress or release the gas pedal the car violently lurches as if slamming on the brakes/gas. This only happens once the engine is at operating temp, and can be fixed (while driving) by turning the car off and restarting. After about 5 minutes the problem starts again. The code it keeps giving me is "P0505 idle air control system".

Things ive done:

Replaced IACV (new not junk yard)
Replaced PCV valve and hose
Removed throttle body and sensors, cleaned throttle body thoroughly
Checked for vacuum leaks the best that I could
Reset ecu multiple times, P0505 is the only code and recurs each time

To me it seems like it may be an electrical problem due to the fact that a simple restart of the car fixes it every time. But I'm far from an expert so I could be wrong. Any suggestions?

Former User

Test the TPS output voltages at closed and WOT.

Ohm test the ECT sensor.

Did you accidentally swap any sensor connectors after the head replacement?