buy a new thermostat there cheap
check that engine temp is actually cool
ecu uses water temp for deciding to use cold start and other things
cold running wears out engines
did you delete any water lines when you did the conversion? ca's have a really complicated water piping layout
do you have the temp sender in the standard location?
cardboard over part of the core works
dazza

yes it can be over cooled. if u are running a thermostat is should still get up to temperature before it opens to let the cool water in anyway, so should still run normal after heating up. if theres no thermostat then thats probably the problem.i think ca's run a pretty high thermostat, like about 195 F, and if its a turbo it will definately use more fuel if running too cold. also if its taking ages to heat up, u wearing out the bearings and bore etc more. u really should get up to operating temperature asap to eliminate as much wear as possible........

Hi ogyris

Yes Poor fuel consumption will be possible unless you get minimum heat required to run the engine smoothly,and also some time when the engine is not heated to required level it might knock while driving, so definitely
you may have less fuel consumption

Thanks
Regards
Sumith

Just wondering if an engine can be
over cooled, say with a larger radiator?

I've noticed now with the colder weather my
CA18 runs much cooler, and the heater is quite poor.
It has a bigger rad.

Can a cool engine have bad fuel economy?

Justin