strange cure for rough running

[4iturbobob]

Been having problems with my 500 running like a bag of bolts.
Came accross a strange cure.
If I put the plug for the coolant temp sensor onto the fuel temp sensor and vice versa..it runs beautifully..
Better than ever before.
So now the plug for the coolant temp which is brown is fitted to the fuel rail and the grey one is fitted to the coolant.
Accoding to the good book and all the imagesi canfind on the net this is wrong.
But it runs so right!!!!
Anybody know why this should be..

Ta
Rob

[A900ss]

Wrong way round in the first place?

[4iturbobob]

Maybe..but everywhere I look it would seem that they are the wrong way round now..
The book does show the brown plug on the coolant sensor.
Baffled !!

[A900ss]

The brown certainly goes onto the coolant sensor ( I replaced mine yesterday) but who knows what has happened in the past?

Just to check the ECU is getting the correct coolant/fuel temps, hook it up to Rover Gauge or similar.

Good luck.

[4iturbobob]

Im guessing it must be..
It runs lovely

[carsy]

A goosed temp sender.

[4iturbobob]

Both sensors check out ok.
Changed them both anyway.
Same result

[Ozstyle]

Hi,

I wouldn't use the plug colour as a defiante guide. My engine coolant sender plug is black, fuel temp sender plug pale blue. The best way to confirm is probably checking the wiring colours (if possible) to the plugs. Range Rover wiring diagram, green/blue red/black for coolant, grey/white red/back for fuel.

I believe the coolant and fuel senders use the same resistance range. I would expect the fuel temp to be lower than the engine coolant temp when running, thus the ECU would over fuel based on the temps seen, if the plugs were fitted the wrong way round.
The ECU relies far more on engine coolant temp than fuel temp, if your car now runs far better with the switched plugs then I would be thinking your coolant sender is at fault or maybe a bad connection between coolant sender and plug.