I rescently got my FC running with no startup or running problems. The temp gauge never goes above 1/2. Coolant is flowing well and I haven't added a drop of coolant since I burped it. I also replaced the water pump when I installed the motor. My question / problem is: My cooling system never creates much if any presure. I can drive the car for an hour and compress the top hose with my hand no sweat. It will be hot and filled with coolant but still not much pressure.



PS: Side not is there a way to tell the S4 / S5 alternator apart?

 

Just though I'd reply. Have the radiator cap tested to see if opens at proper pressure.
Check following for alt-You'll see the wiring is different on the '89/'91
http://www.rx7.org/public/altxref.html

 

Well I check my alt I have the correct S5 80amp. Now just lack of cooling system presure.