Ok I recently attained a 95 SE, ive swapped in an h23a dohc vtec, usdm vtec tranny ect ect. Im running a chipped p28, the car had no radiator in it, so I bought a 2 row aluminum radiator. When I first started the car it was about 74 outside, it took forever to warm up to operating temp, but it finally did, however it will get to the midpoint, the fan kicks on and drops it down immediately, vtec worked everything was good. Now its gotten cold, prob mid to high 30s, now the car will not get all the way to temp, even after idling for 20 mins, driving for 20, and since its not getting to temp, im assum ing even though its a chipped ecu, it still waits till it reaches operating temp before it will allow vtec to enguage. I'm trying to decide if I just wanna put a V-AFC in it, or maybe a higher temp thermostat. kinda weird, im sure in the brutal summers here the bigger radiator will be useful, but for now it kinda sucks.

 

Is there even a thermostat in it ?

 

You probably have a "cold" thermostat or no thermostat or a bad thermostat. Replace it with one from Honda. The aftermarket ones are too spotty to recommend.

LOL "cold...30 deg...florida". For a week?

 

Yeah, sounds like a stuck open thermostat, or no thermostat. Easy to fix before doing anything else!

 

if the thermostat does not fix the issue it is possible in the cooler weather for the radiator to over cool a engine. a little red neck but can always cover rad with cardboard then cut a whole about width of fan in it to help block some of the air passing through the rad. have had similar issues here in canada when the weather gets cold big rads wont let engine get up to temperature .

just a suggestion tho

 

That is an ancient bandaid, and should not be needed on a modern, properly functioning cooling system.

The thermostat will keep fluid from circulating though the rad until it gets hot enough, and should regulate it even with a big rad.

I have a huge Koyo on my WRX, and no problem with it getting up to temp, even in -40 temperatures. I will see a dip for a minute when the thermostat does open, but not enough to lack heat or change how the car runs.

My Prelude also has an aluminum rad with a larger than stock cooling size, and same thing, no problems getting to or maintaining temp.