hard start when hot & stalling

after driving and getting it the engine heated up , if i go into the store for 15 or so i come back out and start it and it will start then the rpm's will drop and if i don't blip the throttle it will stall. if i do blip the throttle it will even out and its fine any ideas?

any help is much appreciated as this is really my only problem with it and its drivng me nuts:runaround:

btw, 90 apv 3.1l tbi 3spd slushbox

Friend gave me a 1994 Luminar APV with 3.1 engine with about 175K miles, as it ran hot with the temperature gauge often going to the 3/4 mark near the red mark. The following fixes were made (1) replace stuck thermostat, and (2) reattach loose hose from the bottom of the air filter canister to the rear of the engine.

Although, it is (1) that fixed a serious stuck closed thermostat, it is (2) that really got the engine to run at normal temperature at the 1/2 mark on the temperature gauge instead of often going up to the 3/4 mark, specially after lengthy parallel parking.

It was a simple visual check with a flash light to find that the crankcase hose was detached from the L-shaped elbow tube just below the front of the air filter canister. The opened hose sucked hot air inside the engine compartment into the crankcase (to flush exhaust gas to the PCV valve) causing the engine to get hotter than normal, which causes stalling during starting when engine is abnormally hot with the temperature gauge at the 3/4 mark (near the red mark) instead of the temperature gauge rarely getting above the 1/2 mark even with lengthy parallel parking on a hot day.

Stuck closed thermostat is found after the upper radiator hose remains cold after starting cold engine for a few minutes with the temperature gauge going up, but the upper radiator hose staying cold. After replacing thermostat, the upper radiator hose gets really hot after about five minutes. The temperature gauge will climb slowly to the half way mark after starting a cold engine. Then the temperature gauge will dip back down to the 1/4 mark after the thermostat opens, and the water pump draws in cold antifreeze from the radiator. After about ten seconds, the temperature gauge climbs back up to the 1/2 mark after all the cold antifreeze had been pumped into the engine. However, with a detached crankcase hose, the engine still often goes above the 1/2 mark, even with a new thermostat.