the minimum is 100 PSI. The maximum variation would be 30% between the 4 cylinders.
Trace the fuel line from the tank to the engine and it should be inline about mid car.
Run a compression check and examine the plugs while you're at it. If you see one or more plugs that are dark and wet, that cylinder isn't firing. If that cylinder also has low or no compression, it has a burned valve.
14:1 compression
A 1993 Pontiac Sunbird head bolt torque sequence recommends starting at one and of the head and alternating to the other end of the head. You should end up in the middle.
It is underneath the thing that says Multi Port FI. Underneath and toward the right side, you should be able to see it when looking at the engine from the back side.
150psi
1 gallon of full streangth should be plenty, butch
Camsaft Carrier cover bolts should be torqued to 72 Inch Pounds. That is for both the OHC and OHV engine. I looked this up in the manual to double check.
Should be located at the rear of the radiator approx. 1/3 from the top unscrew to replace
if both are automatic and both have STOCK exhaust systems it should be alright
Should be in front of the radiator on either side. To easily find it, have a friend honk the horn while you find the source of the sound.
9:1+