OK, I decided to test my throttle position sensor recently. I have access to alldatapro.com here at school and looked up a testing procedure on it. It said to disconnect the tps completely, and turn on the car. it then said to raise the rpms to 2,000, and slowly lower them down to 1000. using a multimeter test for continuity, which should only exist at 1,000 rpms, give or take 150 or so. i have continuity all over the place, so it takes to slowly rotate the sensor until it has the desired continuity. when i rotate the sensor, the rpms of the car go from about 900 in one position, up to 2,000. no matter how slow i rotate it, or play with the idle adjustment screw, turning this sensor acts as if i am twisting the throttle. DOes this mean that the sensor is completely bad? Am I doing something wrong here?
p.s. the reason i am testing this sensor is because the car seems to be running lean some times, but rich other times. I tested the mafs, and engine coolant temp sensor. i am trying to find a factory airbox to put on the car and see if the problem lies in this cone air filter that it has on it. By the way, the plugs were white on the part where they fire and around it, but black and sooty everywhere else. Any help is appreciated
thanks
sohc 240sx, TPS testing question
plug the tps back in. start the car warm it up to operating temp. shut it off and back probe the tps connector with a t-pin from art class. check to make sure you have around .5v at closed throttle. if not adjust till you get it between .4 and .5 volts. set your meter on the 2 volt scale so you get three digits after the decimal. it makes it easier to adjust it. then tighten it up.
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elvis240sx
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- Joined: Sun Sep 08, 2002 11:19 am
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The TPS is a potentiometer: 5 volts is supplied to 1 pin, the others are ground and the variable wiper [moved by throttle].The goal is to set [center wiper] the warmed up idle at 0.44 volts [+-] and when depressed WOT the center wiper should exceed 4.1 volts to ground.
Sometimes the wiper contacts get dirty and or there is not a smooth increase in voltage as the throttle is depressed or a bad noisy spot at some position [like where the throttle might be at 55-65 mph].
Oil impregnated filters can sometimes coat the MAF sensing element.
Sometimes the wiper contacts get dirty and or there is not a smooth increase in voltage as the throttle is depressed or a bad noisy spot at some position [like where the throttle might be at 55-65 mph].
Oil impregnated filters can sometimes coat the MAF sensing element.