Does water temp sender interact with ECU?

[fullmetal]

As title says does the water temp sender interract with the ECU?

Reason why I ask: my engine has slowly but surely been running worse (flat spots, too rich and too lean mixtures) over a period of weeks.. several days of troubleshooting from mechanics, a dyno run, and a day of playing with the TPS only got it partially better. So I thought and thought about what might've changed with the engine.. and the only thing that hasn't been checked was the water temp sender from another 4age to fix what appeared to be a faulty sender in mine (which didn't work btw, water temp gauge in dash still flicks all over the place) - so I unplugged it and the problem seems to have gone! This is still prelimenary, I only drove it for 10 minutes but there appears to little sign of a problem, and what is there might be from changing the TPS or the ECU is learning mixtures again or something.

[Gilly]

the temp gauge sender has no Ecu input it's just a variable resisitor that makes the gauge move. there is a seperate water temp sensor for the ECU which could be your problem.

[fullmetal]

With the wire to the sender disconnected the dash gauge still flicks around the place, but it's range is between cold and the middle rather than the whole range so it's getting an input from somewhere.

[SprinterTRD]

The water sender for the gauge is the one at the front of the engine. If you disconnect this the sensor wire and ground it the guage should go to full scale.

So of you disconnect the wire and the guage is flicking then there may be a short in the sensor wire to the chaassis.

[riceburner]

Wtaer temp gauge sensor in front as you know, and water temp sensor for the ecu is on back of the head. Neither of them interact with each other.

More then likely you getting crossed wires somewhere.

Cheers

Steve