Help please - need EvoScan values for TPS/IPS setup

[crazydriver81]

Well guys,

still have a problem with the engine idle. Idle is not stable and sometimes the engine stalls. If you slightly press the accelerator pedal, engine is loosing some revs, before the car speeds up. It's more noticeable when engine is cold.

So far, we checked for pressure leaks - nothing found.
Checked ISC - clean and working as expected.

So my next idea was the TPS as the behavior with loosing revs is pointing me into the direction, that ECU does not recognize the throttle position correctly, thus leading to either leaning out or overfuelling and stalling.

We checked with EvoScan and I need some values from a correctly running engine to verify my readings. Any help much appreciated. Muchas gracias!

My readings are
Throttle position when butterfly valve closed: 12.1°
IPS: 0
ISC steps: 16-17
RPM: 665

IPS is not changing at all, even if butterfly valve is on WOT. With engine running and shortly pressing the accelerator pedal, engine is hunting for idle and nearly cuts out. ISC is moving up to 40 steps then until idle is stable.

It seems that the IPS is not working at all and the TPS is giving wrong values. Does anyone have had similar issues? Am I correct to assume, that the TPS needs to be replaced?

[Davezj]

TPS will read about the following in Evoscan if everything is stock setup.
throttle closed 12%
throttle WOT 96%

[crazydriver81]

Thanks Dave! :)

What about the Idle Position Switch (IPS). I know that it's basically an on/off switch but when should be on (1) and when off (0)?

[crazydriver81]

OK guys...Problem solved. Had to readjust TPS as the IPS was slightly out. Now everything works fine again.

So if you have issues with unstable idle...worth to check TPS settings.

[Davezj]

when you said you adjusted it what did you actaully do, and why?

[Davezj]

i am just wondering if the TPS actally needed the setup procedure doing. i don't suppose you have reomed it and re fitted it recently.

by that i mean you fit a thin shim in the throttle body open mech on the outside of the throttle body to slightly crack open the butterfly valve.
you set the TPS with the screws that hold it in place, so the resistance of the TPS just flicks open or closed depending what the fully closed state is it goes to the opposite. then fix it in place again with the screws, then when the shim is removed the state of the TPS changes back to the closed position but it changes imediately you press the accelerator.
that should be the correct setup for it.
the full setup prceedure is in the manual for the UK galant in the library and is much better explained then i have just done. so it would be advisable to read that

[crazydriver81]

i am just wondering if the TPS actally needed the setup procedure doing. i don't suppose you have reomed it and re fitted it recently.

by that i mean you fit a thin shim in the throttle body open mech on the outside of the throttle body to slightly crack open the butterfly valve.
you set the TPS with the screws that hold it in place, so the resistance of the TPS just flicks open or closed depending what the fully closed state is it goes to the opposite. then fix it in place again with the screws, then when the shim is removed the state of the TPS changes back to the closed position but it changes imediately you press the accelerator.
that should be the correct setup for it.
the full setup prceedure is in the manual for the UK galant in the library and is much better explained then i have just done. so it would be advisable to read that

Yes, I followed the procedure of the workshop manual. It's sectian 13B / page 184.

[crazydriver81]

when you said you adjusted it what did you actaully do, and why?

Dave, I had some odd issues with the car stalling occasionally plus the rev's dropped a bit before going up, when accelerator pedal was slightly pressed. Plus we had changed to the inlet plenum with the large bore from a FL. So my intention was either the TPS or IPS might be faulty or out of spec. Hence I tried to adjust to hopefully cure that problem.

The real problem was, that the IPS switch engaged too early and causing problems for the ISC to operate correctly. This led to hunting for idle and occassional stalling. But all is fine now and the engine runs like it should.

[MarkSanne]

Good you've got it resolved Stefan! I remember all too clearly my countless attempts at setting the TPS correct when it turned out it was a vacuum leak after all. So anyone reading this: don't mess with the TPS until everything else has been investigated. TPS setup is very delicate / precise and a wrong setting will get you (new) problems!