Yes it does exactly that Mike. It's called the load pot and is used to help the ECU determine the load imposed on the engine by working out how far the throttle is open and engine RPM. Wide throttle plus low RPM indicates heavily loaded engine. It uses this data to then select an optimum timing value from the load maps.MikeT wrote: I can't say for certain but expect the TPS is used to calculate timing, along with other inputs.
It is unlikely to cause rough running.
It should have!!!MikeT wrote: Does your engine have a lift sensor on the third injector??
If duff, and they're not the most reliable of things, they will cause rough idle.
A doddle to test. Disconnect it with the engine ruining and if there is adetectable change in engine note, the sensor is good. If there is absolutely no change then it's suspect.
It can be tested roughly with an ohmmeter; it shoud read in the region of 100 ohms.