April 11, 200718 yr Author Ok cleared codes yesterday and checked codes again today only one left AT THIS TIME. code 31 TPS (or circuit) seems to be a problem
April 11, 200718 yr check the connector plug for bent pins or corrossion, the wiring and then swap in a used one to see if that helps. to check the wiring, leave the engine running and start at the TPS. grab the wires between your fingers and gently roll them between your fingers and bending back and forth. a short will show itself by causing the engine to stall out, idle erratically or if it's running poorly it will run good when you hit that spot. if this happens you'll have to replace the wire. continue this procedure, working away from the TPS for as long as you have access to the wire. bad wiring is usually in the first couple inches. annoying, but not hard to do and very low cost. you could attempt opening up the TPS and seeing if you can clean up the contacts. i'd have an extra one on hand though in case you screw it up.
April 11, 200718 yr Author check the connector plug for bent pins or corrossion, the wiring and then swap in a used one to see if that helps. to check the wiring, leave the engine running and start at the TPS. grab the wires between your fingers and gently roll them between your fingers and bending back and forth. a short will show itself by causing the engine to stall out, idle erratically or if it's running poorly it will run good when you hit that spot. if this happens you'll have to replace the wire. continue this procedure, working away from the TPS for as long as you have access to the wire. bad wiring is usually in the first couple inches. annoying, but not hard to do and very low cost. you could attempt opening up the TPS and seeing if you can clean up the contacts. i'd have an extra one on hand though in case you screw it up. Wow thanks alot Gary hopefully I won't screw up mine. I will try to do that tonight when i get home. Does the TPS have it's own connector to the ECU? Hopefully it will be somewhat obvious when I try the rolling trick tonight. I have a butt connector set and crimpers so if I do find faulty wiring I will be able to fix it on the spot
April 14, 200718 yr Author Ok I tried testing out the TPS wires by rotating them in my hands, and seeing if there was a short of any kind = no difference. I followed the wires to the harness and cleaned that up = no difference. Came back to this board and did some searching on TPS = didn't find much. Thought about it with my feeble mind a little bit I remembered one thing. The TPS was marked with white crayon at screw positon, which means some mechanic worked on it and either replaced or removed the TPS at some point. The QUESTION: What would happen on a subaru if the original TPS was a non inverted TPS and it was replaced by an inverted TPS????? Since the TPS is working correctly and I don't really see a problem with the circuit I'm hopeing that an inverted TPS would screw up a car built for a non inverted TPS. Thanks in advance.
April 14, 200718 yr Ok I tried testing out the TPS wires by rotating them in my hands, and seeing if there was a short of any kind = no difference. I followed the wires to the harness and cleaned that up = no difference. Came back to this board and did some searching on TPS = didn't find much. Thought about it with my feeble mind a little bit I remembered one thing. The TPS was marked with white crayon at screw positon, which means some mechanic worked on it and either replaced or removed the TPS at some point. The QUESTION: What would happen on a subaru if the original TPS was a non inverted TPS and it was replaced by an inverted TPS????? Since the TPS is working correctly and I don't really see a problem with the circuit I'm hopeing that an inverted TPS would screw up a car built for a non inverted TPS. Thanks in advance. How EXACTLY did you test the tps? nipper
April 14, 200718 yr Author How EXACTLY did you test the tps? nipper http://endwrench.com/images/pdfs/Fuel.pdf CLosed TPS is supposed to be at 0-0.5 volts Open TPS is supposed to be at4.5-5 volts However mine is exact oppisite. pins 2 and 4 on a 4 pin TPS connector with ignition on.
April 14, 200718 yr http://endwrench.com/images/pdfs/Fuel.pdf CLosed TPS is supposed to be at 0-0.5 volts Open TPS is supposed to be at4.5-5 volts However mine is exact oppisite. pins 2 and 4 on a 4 pin TPS connector with ignition on. Use the Haynes version. You also need to check the sweep as there can be a dead spoot in the sweep. Are you sure you have your leads in the right position? nipper
April 14, 200718 yr Author Use the Haynes version. You also need to check the sweep as there can be a dead spoot in the sweep. Are you sure you have your leads in the right position? nipper I have the haynes version. That is the method I used. I'm not sure what u mean by check the sweep.
April 14, 200718 yr I have the haynes version. That is the method I used. I'm not sure what u mean by check the sweep. Using an analog meter, move the TPS arm to make sure there is an even movement of the neddle, that there are no spikes and no dropouts. nipper
April 14, 200718 yr Author Using an analog meter, move the TPS arm to make sure there is an even movement of the neddle, that there are no spikes and no dropouts. nipper So my $300 fluke DMM won't work ?
April 14, 200718 yr So my $300 fluke DMM won't work ? nope cause my 1200.00 fluke wont do it either. For alot of things on the car you need the 12.00 analog meter from radioshack
April 14, 200718 yr Author So again before I go out and buy new stuff. Back to the original question. What would happen on a subaru if the original TPS was a non inverted TPS and it was replaced by an inverted TPS?????
April 16, 200718 yr Author Ok I'm going to get a used TPS to throw in the car. While that's being done does anyone here have a 90-94 legacy that knows or could find out if their TPS is 0-0.5 volts closed throttle? Or if it's actually 4.5-5 volts. Thanks if anyone responds.
April 17, 200718 yr It really doesn't matter which style of TPS you have. The main thing is that it works smoothly through the range of resistance. Instead of measuring the resistance I would look at the voltage through the whole range. You should be able to catch rough spots looking at the fast response bar on the meter display of the Fluke.
April 17, 200718 yr Author It really doesn't matter which style of TPS you have. The main thing is that it works smoothly through the range of resistance. Instead of measuring the resistance I would look at the voltage through the whole range. You should be able to catch rough spots looking at the fast response bar on the meter display of the Fluke. Yeah but if my TPS is inverted then at fully open it should be at 0-0.5 volts. Mine isn't full open it's at 2.8 volts. But your saying it doesn't matter what sytle of TPS I have but if the car came stock with a TPS that at closed was sitting at 0-0.5 volts and was replaced with a TPS that at closed sits at 4.5-5.0 volts it would seem that would definetly make the computer a little confised. Unless someone here knows for sure that the computer will automatically adust for a change like that it seems I need to a. Find out what kind of TPS came stock with that car. b. Get a new TPS that at fully closed sits at 0-0.5 volts. and at fully open sits at 4.5-5.0 volts or inverse depending on what kind of unit I need. I could check the sweep this weekend to see if it's dropping signal but it still doesn't change the fact the unit isn't operating properly already from the tests I've run.
April 18, 200718 yr I assume that the car was running ok at one time with the current sensor. I don't think you can use the other type TPS without changing out the ECU also. Going by the 2.8 volt reading you took it seems that the wiper is either not making the full travel of the resistor or, the sensor is bad.
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