[decprelude]

Hello,
I've been having a problem with my 95 integra GS-R running cold(at least, I think it is). I've searched the forums but can't seem to find a solution.
Symptoms:
temp gauge at or near C
luke warm, not hot, heat from vents
no vtec
temp needle falls when heat turned on
temp needle falls when cruising on highway
car seems to idle normally(~900rpm) after several minutes
worse MPGs on last fillup(usually 30+, now 26)
fan will turn on with the A/C
If I sit and hold the rpms at about 3K for maybe 10 mins the needle will at most move up to about 1/8 and the fans will come on briefly. As soon as I lift off the pedal the fans go off and needle returns to C and never climbs again.

Tried:
replaced thermostat(twice)
repaced temperature sensor

Everyone I've asked seems to think that I need a new thermostat, but I've replaced that twice. I think the gauge is working since it will moves and doesn't simple sit on C. Also, I don't get any heat.

Any ideas? Any help would be greatly appreciated.

Thanks.