Throttle Pot Reading High

[Harveybw]

Hi All,

Sorry if this has been covered, I’ve done quite a bit of searching but can’t find my fault listed.

When plugging rover gauge in my throttle position is showing 24% on corrected, 34% absolute.

Even off the car, the reading are the same, it won’t go lower. This is a new/old sensor to replace one with wiring issues and shows good readings when on another car.

Anything else that could be causing this? ECU fault? Bad Earth?
I’ve seen they can be adjusted but if the TPS itself won’t turn any lower then am I right in thinking it won’t adjust?

Thank you!

[Belle427]

This below may help, you can elongate the holes in the plastic to gain the movement but you need to be careful.
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[blitzracing]

A broken earth wire will cause a constant high voltage on the sense wire back to the ECU.

[Steve_D]

The TPS earths at the ECU pin 25. It shares this earth with the MAF and both the coolant and fuel temp. sensors (red/black wire).

Steve

[bobfather]

If the wire insulation has become brittle due to heat soak is is likely that the insulation has cracked near the sensor. This concentrates flexing in one spot causing work-hardening of the copper strands. High resistance and ultimately open circuit can occur at that location. With a little Dremel digging you can expose the track contacts in the sensor and solder new wires in place. If you do this I would advise also using epoxy resin to hold and protect the first couple of centimetres of new wire and add heat sleeving to the rest

[Steve_D]

Should have added that all of these earth wires come back to the blue loopback connector in the footwell.

A simple test would be to run a test wire between the red/black at the tps to the red/black on one of those other sensors.

Question..are the other sensors mentioned working OK?

Steve

[Harveybw]

Thanks for the replies all some cracking ideas there.

I have recently changed the ECU temp sensor, as whilst it was working the plastic nut portion was very loose. I’ve gone with an all brass one now and it’s spot on. MAF seems fine, normal readings but can’t get the car warm to check properly. As long as I can get an idle from it, I can check properly.

This leads me to believe my ham fists have messed something up, as throttle pot was spot on before and the car drove really well. Now it barely ticks over.

I’ll get my meter out and start testing connections and earths as mentioned.