Sup guys, I have a 95 obd1 b18b I took out of my integra and put into 92 bubble. I have a problem with the thermostat not opening and my car over heating. I have an after market temp gage installed so I know exactly what temp I'm at. Right now I'm running without the Thermo just so I can get around. I've looked all over the forums for my specific issue and i haven't found anything. Here's the issue:
When I did the swap right when I turned the car on a let it run after filling the engine with coolant I noticed the thermostat wasn't opening. Made sure to bleed all air out of system. Even filled bottom hose let it run, but the thermostat never opened. The car was running at 220 F before I turned it off. I went bought a new Thermo installed it correctly. Filled rad, bled air, let it run. Still wasn't opening. The bottom hose still cold and top hose so hot. Bottom of rad is ice top is hot. Heard about faulty thermos went and bought another. Same thing happened. So I thought maybe there's a clog in my rad or air so I swapped my half rad I have and hooked up the integra rad. Same deal bottom cold top hot. Thermo not opening.
So here's the thing. I'm thinking my water pump could be weak. Because the water pump is working and taking in fluid but maybe it's not creating enough pressure to help open Thermo? I mean the water is hot!!! So it's not a temp problem at the Thermo! Any help much appreciated.

first post btw! Sup guys

 

The water pump has nothing to do with when/if the thermostat opens, engine coolant does, and if your hitting 220F it should be opening unless the thermostat is a 220F or higher.

Have you tested the thermostat in a pot of boiling water?

Is the thermostat installed upside down, don't know if it's possible on your engine?

The above does not mean your water pump is good, how many miles on it?94

 

160+ miles on it. And I triple checked trust me the Thermo was installed correctly. Had 2 people come over and confirm lol

 

And the Thermo I got both times is 180

 

If you don't have one borrow a laser temp. gun and check the temp. at the thermostat housing.

Where is the aftermarket temp. gauge pickup sensor? 94

 

It's on the side of the head under the distributor it has one wire going to it. And okay I'll try to check housing temp. The temp gage was in the car before my motor was. So would it read the wrong temp because it's working off the stock sensor?

 

What is the make and model of the temp. sensor, a lot of aftermarket gauges will need their own sensor.

I have that problem on a 73 GMC P/U I am wiring for a customer, it is an AutoMeter, can't remember the model, but had to order the sensor for it. 94

 

Are the fans coming on? Sounds like air in the system, try sqeazing the bottom hose to get the fluid pumping more.

Did you put the heater on full blast when bleeding the air out the radiator? I usually put the heat on high and let it idle with the cap off the radiator till all the bubbles are gone and fans turn on and hoses are hot.

 

The water pump does not use pressure to help open the thermostat, heat from the engine heats up the coolant, which is transferred to the thermostat and makes it open. Did you turn your heater in the hot position? You have air in the system for sure. Get another thermostat (preferably oem) add the coolant again, make sure your fans are working, they should turn on after about 15 minutes idling. Check for leaks.. A small pine hole leak will introduce air skyrocketing temps quickly..replacing the timing belt and water pump isn't a bad idea either way though

 

It's possible that the thermostat you've installed is opening at too high of a temperature or not opening enough, and this is causing the car to overheat by restricting water flow.

I would heat it up in a pot of water and check the temperature with a meat thermometer. The OEM specs are that it should be fully open (>= 8mm) at 194 F I think.