Where do I find the Throttle Position Sensor?
Discussion
My car runs very nicely, until the engine warms whereby I get a shunting effect when pootling around at 2k revs.
Essentially when I ease of the throttle around this rev range, the revs dip suddenly and vice versa when I put the gas on. I end up kangaroo hopping up the road!
I have read somewhere (and advised by OnlyMX5's) that the issue could be the TPS switch....now, where do I find it and what should I do with it once I have found it?
Thanks, as ever.
L83
Essentially when I ease of the throttle around this rev range, the revs dip suddenly and vice versa when I put the gas on. I end up kangaroo hopping up the road!
I have read somewhere (and advised by OnlyMX5's) that the issue could be the TPS switch....now, where do I find it and what should I do with it once I have found it?
Thanks, as ever.
L83
I would imagine the TPS is located on/near the accelerator pedal, as that is after all the variable element that controls throttle opening, but I'm not an expert so I'm sure someone else will come along and confirm/shoot me down in flames shortly.
As for what you can do with it once you've found it, I would imagine that getting a mulimeter and checking its output under the conditions where the fault appears, from pedal fully up to fully down would show up a faulty sensor. Which model do you have - I believe the sensor range for the Mk2 and later is 0-5V, but earlier cars only have an on/off signal?
You could actually check that TPS signal without even knowing where the TPS is, as the ECU wiring diagrams tell you which wire going into the ECU comes from the TPS, so you could check it there. I believe you can also test it with the engine off and the key in the pre-ignition position, but you need to be careful not to damage your coils by having the car in pre-ignition for too long.
As for what you can do with it once you've found it, I would imagine that getting a mulimeter and checking its output under the conditions where the fault appears, from pedal fully up to fully down would show up a faulty sensor. Which model do you have - I believe the sensor range for the Mk2 and later is 0-5V, but earlier cars only have an on/off signal?
You could actually check that TPS signal without even knowing where the TPS is, as the ECU wiring diagrams tell you which wire going into the ECU comes from the TPS, so you could check it there. I believe you can also test it with the engine off and the key in the pre-ignition position, but you need to be careful not to damage your coils by having the car in pre-ignition for too long.
Edited by youngsyr on Tuesday 17th August 12:37
youngsyr said:
I would imagine the TPS is located on/near the accelerator pedal, as that is after all the variable element that controls throttle opening, but I'm not an expert so I'm sure someone else will come along and confirm/shoot me down in flames shortly.
Makila2A said:
It's on the throttle body, on the opposite side to where the throttle cable connects. The symptoms you describe could well be a dodgy TPS.
Only thing is, that they are adjustable so you'll need a multimeter and whatever the required specs are to set up the new one.
HTH
I stand corrected (said the man in the orthopaedic shoes).Only thing is, that they are adjustable so you'll need a multimeter and whatever the required specs are to set up the new one.
HTH
MX-5 Lazza said:
It could just as easily be plug leads, coils or the engine temp sensor on the back of the block though. Not sure how you test a TPS but I'd suggest testing it before you try to do anything to it.
What do you have controlling fuelling on your car?
Emanage Blue.What do you have controlling fuelling on your car?
Might swap my leads for some Magnecor jobbies - they were excellent on my old car.
MX-5 Lazza said:
So is this just when rolling on/off throttle or is it more when going on/off boost?
Just when rolling on / off throttle. It is usually at low speeds, in say 2nd or 3rd at 2k revs (in fact it only occurs around the 2k rev mark).It makes going round tight mini-roundabouts a nightmare if I have to modulate the throttle through it - tries to throw me in the hedge!
Legend83 said:
MX-5 Lazza said:
So is this just when rolling on/off throttle or is it more when going on/off boost?
Just when rolling on / off throttle. It is usually at low speeds, in say 2nd or 3rd at 2k revs (in fact it only occurs around the 2k rev mark).It makes going round tight mini-roundabouts a nightmare if I have to modulate the throttle through it - tries to throw me in the hedge!
Legend83 said:
Just when rolling on / off throttle. It is usually at low speeds, in say 2nd or 3rd at 2k revs (in fact it only occurs around the 2k rev mark).
In that case the emb is unlikely to be contributing to it as it should do nothing until it sees boost assuming the O2 clamp is set up correctly. At least that rules that out!Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff