You remove the old one and put a new one
Look where the upper radiator hose connects to the engine and you should find the thermostat housing.Look where the upper radiator hose connects to the engine and you should find the thermostat housing.
Look under the vehicle at the junction of the 3 cables
Does it turn over? Does it have: fuel spark compression?
2 men.. under 1/2 hr.. its time consumming setting it into place and gettin the gaps and shims (if needed) right
Use a 'universal joint' socket adapter, a short extension, and a 3/8 ratchet
remove upper motor mout bolts and pry forward.
Purchase a repair manual at most parts stores, ( around $12 ) for detailed instructions on this and many other repairs.
check the ignition module, it's in or around the rotor
you have brake fluid leak in your brake system somewhere that need to be check.
1990 was before GM switched to using Dex-Cool extended life coolant, so any of the traditional green ethylene glycol or universal coolant/antifreezes would work perfectly. Any brand will suit the car well.
2 possibilities are 1.) the voltage regulator or 2.) the worst possible answer, wiring gremlins draining on ur elec. system i.e. (improperly wired stereo system) ~Chuck~
Remove wheels re-install 2 lug bolts to hold rotor in place Loosen caliper mounting bolts (2) Remove 1 caliper bolt to allow caliper to swing without stressing brake line Remove front brake pad Use "c" clamp on rear brake pad to retract piston Remove rear pad Install new pads swing caliper back in place tighten mounting bolts (35 ft lbs) Install Wheel DO NOT MOVE CAR UNTIL BRAKES ARE PUMPED TO RESET PADS TO ROTOR