TPS Shudder Issues

[someguy360]

Hi Guys.

As many of you know I have been trying to find this annoying shudder on very light throttle on the VS for months and months now.

After ensuring all bushes, mounts, trans, leads, coils DFI etc was fine I have today moved on to sensors.

I started unplugging them one by one and going for a drive (except the CAS obviously as the car won't start without it)

I finally pulled the last plug off in the process of elimination which happens to be the TPS plug, took the car for a drive....ran like an absolute dream without the TPS plugged in.

Idle was 10x smoother, shifts & throttle were much more responsive etc it was just amazing....and from what I could feel no shudder/surging what so ever.


I have replaced the TPS itself with a couple that I had spare which made no difference, I also tried my spare throttle body but no difference which leads me to think its the wiring/plug etc.


Does anyone have any ideas on how to go about testing the wiring for the TPS or should I take it to an auto elec (I have multi meter and test lights etc but when it comes to wiring I get uneasy, I don't work on wiring etc on injected cars so much....so many wires...I am used to working on carbed engines)

For now I will leave the TPS unplugged so I can drive comfortably, will this do any damage if I do?

Thanks

 

[Jonah 101]

If I disconnect my TPS the car has a shocking flat spot, runs like a total bag O shite.

 

[someguy360]

If I disconnect my TPS the car has a shocking flat spot, runs like a total bag O shite.

Odd, mine feels 10x better without it, although I haven't opened it up alot, this was just around town where my shudder/surging is most noticable

 

[Jonah 101]

I have never driven with it unplugged, but the car didn't like it.

 

[someguy360]

I have looked on other forums by googling the same issue (honda forums and the like) some have recommended running new wires from the TPS to the ECU.

Does anyone know which wires on the ECU loom run the TPS?

Also anyone have any idea on testing the current TPS wiring?

 

[someguy360]

Just took it for a drive when it was cold and it didn't shift properly etc so I plugged it back in.

The shudder came back and it started idling rough again when I plugged it back in

ideas?

 

[SavVYute]

Investigated the IAC valve on the throttle body yet? They can stick with carbon build up, or the O ring seal can leak.

 

[someguy360]

I have replaced the IAC, that wouldn't cause the shudder while driving though, only while idling.

Has to be something TPS related as when the car is warm and I unplug the sensor the car runs great.

After taking it for another drive it seems when I am sitting at 50-60km/h it runs fine for a short time, then the revs seem to drop down a little (only 50-100 RPM) and thats when the shake comes in, the revs don't seem to drop down when the TPS is disconnected

 

[IBLOWN]

I think the gregorys manual gives you volatge readings at certain throttle positions. I'd be checking the first. Im pretty sure the TPS wiring is tied up with the crank sensor and DFI module.

 

[BlackVXGTS]

The explanation below and diagrams should help you if the TPS is causing your problem. Is you car manual or auto?

THROTTLE POSITION (TP) SENSOR

The Throttle Position (TP) sensor is connected to the throttle shaft on the throttle body unit. It is a potentiometer with one end connected to 5 volts from the PCM and the other end to PCM earth. A third wire connects from a sliding contact in the TP sensor to the PCM allowing the PCM to measure the voltage from the TP sensor. As the throttle is moved (accelerator pedal moved), the output of the TP sensor changes. At a closed throttle position, the output of the TP sensor is below 1.25V. As the throttle valve opens, the output increases so that, at wide-open throttle (WOT), the output voltage should be about 4 volts.

By monitoring the output voltage from the TP sensor, the PCM can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor can cause intermittent bursts of fuel from the injectors, and an unstable idle, because the PCM interprets the throttle is moving.

The TP sensor is not adjustable and there is not a set value for voltage at closed throttle because the actual voltage at closed throttle can vary from vehicle to vehicle due to tolerances. The PCM has a special program built into it that can adjust for the tolerances in the TP sensor voltage reading at idle. The PCM uses the reading at closed throttle idle for the zero reading (0% throttle) so no adjustment is necessary. Even if the TP sensor voltage reading was to be change by: tampering, throttle body coking, sticking cable or any other reason, the TP sensor will still be 0%. The PCM will learn what the closed throttle value is every time the throttle comes back to closed throttle. The new closed throttle value will be used by the PCM and no driveability complaint will be present because the PCM learned a new setting. A failure in the TP sensor circuit problem will set DTC 21 or DTC 22. If the internal spring in the TP sensor should fail, the TP sensor will be stuck high. A sticking TP sensor should set DTC 19.