Chasing down oil leaks...
Join Date: Nov 2001
Location: nearly Kingaroy, Qld.
Re: Everyone with a 3.9lCPI engine should read this!
I am sooo trying this when I can get hold of a mulitmeter.. I just also read in the Haynes manual about testing the TPS and it says the voltages should be between 0.7 and 4.4V. But I think the gregory's is a better manual..
Also there is a test for smoothness from closed to wide open - that may be good for picking up flat spots in acceleration maybe..
This maybe a violation of copyright but I don't think Haynes will sue me.. (Hopefully!!)
Throttle Position Sensor (TPS)
The throttle position sensor (TPS) is located on the end of the throttle shaft on the throttle body (MPEFI) or fuel charge housing (CFI). By monitoring the output voltage from the TPS, the ECU can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TPS can cause intermittent bursts of fuel from the injectors and an unstable idle because the ECU thinks the throttle is moving. Any problems in the TPS or circuit will trigger a code 23, 53 or 63.
*On CFI models perform the following at the TPS electrical connector.
*Using straight pins or paper clips as required, backprobe the TPS electrical connector. Attach the negative lead earth and the postive lead to the sensor wire.
*Turn the ignition key ON, (engine OFF), the sensor should read approximately 0.7V with the throttle closed. Now manually open the throttle to wide open position, the sensor voltage should increase to approximately 4.4V
*Check the TPS reference voltage. With the ignition key ON (engine OFF), connect the positive probe of the multimeter to the orange/black wire. There should be approximately 5.0V present. If no voltage check for a blown fuse, etc..
*Check the resistance of the pententiometer within the TPS. Disconnect the TPS electrical connector and working on the sensor side, connect the probes of the multimeter to the orange/black and gree/black wires. With the throttle valve fully closed the TPS should read approximately 3K ohms.
*Now open the throttle with one hand and check the resistance again. Slowly advance the throttle to the wide open position. The resistance should be approximately 500 ohms. The pententiometer should exhibit a smooth change in resistance as it travels from closed to fully open throttle. Any deviations indicate a possible worn or damaged TPS.
Hope that helps anyone that might want to try it..
1988 EA Falcon Pearl Green
Head gasket replacement count - 1