So after I finished my V5 STi swap I have a few small issues. The car runs great under load, but the idle will search between 500-1500 RPM. Sometimes it will smooth out and idle normally, but most of the time it bounces around. Also while cruising down the highway at a consistant speed, you can feel the car lose and gain momentum slightly. Its like a pulsating feeling. None of the gauges change or anything, but you can physically feel the car lose momentum. Its really strange. I think these two issuses may be MAF or Throttle Position Sensor related. The TPS is rather expensive so I hope I can rule that out. I also haven't used my keyless entry since the swap because in the mornings when I hit the unlock button one of the two 10 amp fuses under the dash pops. I'll replace them and it will work fine when I head home in the afternoon. It seems related to water/condensation because it also happens when it rains. Also when it rains the dash illumination fuse pops. I have no idea why. Any help would be appreciated. I would be willing to drive the car to Atl if anyone has ideas or would be willing to help out.
sounds like an air leak to me. as for keyless...tracing wiring with diagrams is going to be your best bet.
That sounds like a TPS to me, but I'm NOT a mechanic. Especially the 500-1500 thing. Isn't there a way to monitor throttle position with a laptop?
yes ecu explorer has something like that under it's real time data viewer, you can also check to see if the position sensor is functioning
Check out this thread for the idling issue; http://forums.nasioc.com/forums/showthread.php?t=781242 Make sure the car is cold. That way the gasket will not get deformed and you may be able to reuse.
His is version 5 JDM. It will have the IACV detached and on the manifold somewhere. They did not do the integrated IACV on TB until version 7 stuff came along. An air leak at the manifold will cause a hunting idle. TPS issues will throw a CEL. Check for air leaks first.