Hi,

I did post this in the electrical section but it didnt get many views, so ive put it here aswell. If its in the wrong place can the mods please move it.

Basically,

When i put my key in the ignition and turn the key the needle on my rev counter jumps upto 800rpm and sits there untill i start the car...

Have noticed it a lot more during the cold spell weve been having, and i dont recall it doing it when i first bought the car (4 months ago).

Any ideas???

 

All i can think of is that you are getting a current to/from the tacho sensor. As 800rpm is tickover, possibly a short due to damp in a plug/socket.
I've had a look at the pin outs but it's of no real help as it lists 0v ignition on or off.

I don't know where abouts under the bonnet to look for the tacho sensor connection. Perhaps a good dowsing with WD40 or similar.

 

Ill have a look around. I was also thinking about maybe a dodgy earth? As when i have my wipers going, the clock (time not instrument clocks) flickers with the wiper? Ive had a look at the earth connections on the struts, and the wiring is a greeny blue colour.

 

Yeah, defo sounds possible. As i said, the tacho should not receive a signal until the engine is started.
Get them off and give them a good clean, can't do any harm