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So, I resolved my high and erratic idle issues and the car now runs GREAT!
Feels like I gained an extra 5hp at the wheels, but now I'm trying to check/set the TPS and getting very confused. This is what I have deduced:
The TPS has 3 wires, each attached to a long, thin metal blade. The bottom wire is ground (-), the middle wire is signal (+) and the top wire is reference (REF). The operation of the TPS is basically just a double contact switch and there is no variable voltage that is sent over the signal wire. The middle blade (signal) rides in a plastic cam groove that's attached to the throttle shaft. At idle, the middle signal blade (+) contacts the bottom ground blade (-). You should have continuity between these two blades at idle. Once the throttle shaft is slightly opened (so that the throttle stop is off the dashpot a few thousandths of an inch) the middle signal blade is raised off the ground blade and the connection is broke (continuity is lost). As the throttle shaft is rotated through it's movement, the middle signal blade is gradually pushed closer toward the top reference blade and farther away from the bottom ground blade. There should be NO continuity between ANY of the blades through this movement. Just before WOT (say at about 7/8 of WOT) the middle signal blade contacts the top reference blade and you should have continuity between them. Since the top reference blade has 5 volts to it at all times when the key is on, you should have 5 volts on the signal wire at WOT and no voltage at any other times.
So, how do you get the .5 to 1.0 volt on the signal wire at idle? All I can think of is that there is a small current on the signal wire itself?
When I test my TPS, I get 4.78 volts on the reference wire, 0.00 volts on the middle signal wire (+) at idle and like -12.08 volts on the middle signal wire at WOT (when it's connected to the reference wire that has 4.78 volts)? I have (2) different TPS sensors and get the same results with each. Do both sensors just happen to be bad? What am I doing wrong? I'm testing the actual blades themselves (with the cover off the side of the sensor). Do I need to be testing them on the back side of the plug?
Feels like I gained an extra 5hp at the wheels, but now I'm trying to check/set the TPS and getting very confused. This is what I have deduced:
The TPS has 3 wires, each attached to a long, thin metal blade. The bottom wire is ground (-), the middle wire is signal (+) and the top wire is reference (REF). The operation of the TPS is basically just a double contact switch and there is no variable voltage that is sent over the signal wire. The middle blade (signal) rides in a plastic cam groove that's attached to the throttle shaft. At idle, the middle signal blade (+) contacts the bottom ground blade (-). You should have continuity between these two blades at idle. Once the throttle shaft is slightly opened (so that the throttle stop is off the dashpot a few thousandths of an inch) the middle signal blade is raised off the ground blade and the connection is broke (continuity is lost). As the throttle shaft is rotated through it's movement, the middle signal blade is gradually pushed closer toward the top reference blade and farther away from the bottom ground blade. There should be NO continuity between ANY of the blades through this movement. Just before WOT (say at about 7/8 of WOT) the middle signal blade contacts the top reference blade and you should have continuity between them. Since the top reference blade has 5 volts to it at all times when the key is on, you should have 5 volts on the signal wire at WOT and no voltage at any other times.
So, how do you get the .5 to 1.0 volt on the signal wire at idle? All I can think of is that there is a small current on the signal wire itself?
When I test my TPS, I get 4.78 volts on the reference wire, 0.00 volts on the middle signal wire (+) at idle and like -12.08 volts on the middle signal wire at WOT (when it's connected to the reference wire that has 4.78 volts)? I have (2) different TPS sensors and get the same results with each. Do both sensors just happen to be bad? What am I doing wrong? I'm testing the actual blades themselves (with the cover off the side of the sensor). Do I need to be testing them on the back side of the plug?
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