RV8 Temp sender confusion

[captiv8ed]

After doing my cam, my temp is reading 90 degs almost immediately after startup, going on to 120-130 when warmed up. Fans come in and out as normal. I've checked connections (ok), shorted the lead to earth (max reading on guage) and as a last resort, used the stubby spare temp sender on the inlet manifold.I found this...

www.pistonheads.com/gassing/topic.asp?h=0&t=221941&hw=+%2Btemp+%2Bsender

... and have read that adding a 120 ohm or 200 ohm var. resistor allows you to use the spare sender. Question is, looking at the two graphs, I can't see 120 ohms making much of a dent in the reading. I put the lead directly onto the stubby one last night, thinking it won't be right - but better than what I've got - but it was the freakin same! Should I see a difference even without the resistor? Any help gratefully received.

[rev-erend]

So to ask the obvious question :

Is this reading any different to what you had before the cam change.

Did you change the sender ?

Perhaps an earth cable was not re-attached..

[CaptiV8ed]

Never touched the sender and it was behaving nornally before the strip down. The earth connection is fine I believe, because if you short the lead to the engine, it gives the same result as when the sender is warm - right over to 130 degs. I've just bought a 250 ohm var. resistor and will try to see if affects things this afternoon!

[ozstyle]

Hi,
since you disconnected the wiring maybe you now have a poor connection between sender and connector, may just need to clean the connection and make sure it is a tight fit. Could also be an air lock in the system which just needs bleedin, I had elevated temp readings after refilling after a cam change untill I fully bled the cooling system.

[rev-erend]

To me it sounds like you are trying to fix a problem that is not there..

Double check the temp with a lazer temp gauge..

90 degrees directly after startup is just impossible.