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Today I was checking the voltage of my TPS. Checked reference - 5 v(top wire -black and bottom wire) when I probed the top and middle wires I got a reading of 4 v and decreased to below 1v when I opened the throttle. Is there something wrong with the sensor or me? I did the procedure as I have read on other posts and in the manual. KOEO
The reason I was checking this is, when I am under the hood with the engine running and push the throttle there is a slight hesitation almost acts like it wants to die, just for a second, before it revs up.
Simplest way to test for a bad TPS is to pull the codes. The TPS should smoothly go from approx 1 volt at idle to approx 5 volts at full throttle. Move the throttle slowly as you watch the voltage, any jumping around of the voltage means the TPS needs replaced.
Simplest way to test for a bad TPS is to pull the codes. The TPS should smoothly go from approx 1 volt at idle to approx 5 volts at full throttle. Move the throttle slowly as you watch the voltage, any jumping around of the voltage means the TPS needs replaced.
Thanks for the reply. I was more curious as to why when I did the test the voltage was reversed. It started at 4-5v at idle and dropped to below 1v when I opened the throttle. I am not sure if there is some thing wrong with the TPS or the way I tested. This is puzzeling. I hope some one out there will have some idea as to why this is happening. Is there the possibility of wires being reversed?
If I remember correctly the "signal" wire is the center wire & you need to test between there (shove a sewing needle thru it)and any ground. But take a look at the "technical information sticky" at the top of the Ranger forum & click on "TPS testing"
OK I just went out and did the test again. Top wire is the black wire. Bottom 2 wires not sure of the color because of fading. Black wire to bottom wire (reference) -5v. Top wire to middle wire - (at idle) - 4-5v and as I open the throttle moves smoothly to -1v. If I use the red lead (volt meter) on the black wire the voltage switches from neg to pos. But still starts at 4-5v at idle and drops to 1 or less v as I open the throttle. I am still puzzled.
I just got done testing the resistance. I disconected the harness from the TPS and checked the ohms. At idle 3.12 ohms (good) then when I opened the throttle instead of increasing to 350 ohms (open resistance) it dropped (gained resistance) to 1 or so ohms. Any body????
Thanks for the reply. I was more curious as to why when I did the test the voltage was reversed. It started at 4-5v at idle and dropped to below 1v when I opened the throttle. I am not sure if there is some thing wrong with the TPS or the way I tested. This is puzzeling. I hope some one out there will have some idea as to why this is happening. Is there the possibility of wires being reversed?
At this point I think your best bet is to put it back together & pull the codes. If the wiring is reversed, you will know it about 2 minutes after you have hooked up the scanner as it will give you a TPS voltage too high or too low code.