My Pontiac grand-am runs perfectly when warmed up but when it sits overnight and cools down the engine spins without any compression at all-eventually it will start after some chugs and barfs and misses-after it starts it runs beautifully with good power and no tailpipe smoke-it continues to run and start normally all day long but after it sits all night and cools down the problem reoccurs- ignition system good with new spark plugs-any ideas

Still sounds like a fuel starvation issue - pump, filter or regulator. Check pressure at tthe engine.

Ignition module may be bad ! Watch this video , this a four cylinder engine , doesn't matter . Test it the same way GM Ignition System diagnosis 1988 Olds Cutlass

try changing fuel filter as it may be clogged. the time you are waiting may allow deposits to settle back in line.

crank pos. sensor or maf sensor ck. the fuel press reg. also

Start by removing the sparks and wire set. Mark each wire with a piece of tape as you take them off. Take a compression reading on all cylinders. They should be over 120 psi and within 20 psi of each other. Change the oil and filter, checking the oil for water and metal particles. If the gasoline has been sitting that long I would fill it with fresh fuel. Change the air filter, plugs, wires, etc. Check the cooling system for leaks, drain and refill with new antifreeze. Assemble everything and have a small amount of fuel to prime the engine if needed. Make sure the battery is fresh and fully charged. Fire her up, let it get warm while checking for leaks, smoke, overheating. Bring to a smooth idle.

Try removing the radiator cap when the engine is cool and top off the coolant level. Start the engine with the cap of and let it run to operating temperature which is when the thermostat opens. If you lightly grab the upper radiator hose. If it is cool or warm, the thermostat has not opened. If it is hot, the thermostat has opened. At that time have someone assist you by sitting in the car to rev the engine up (1800 to 2000rpm) and hold it there while you once again top off the radiator and tighten the cap. DO NOT BRING THE RPM DOWN TO IDLE WITHOUT HAVING THE CAP ON TIGHT! THE HOT COOLANT WILL OVERFLOW FROM THE RADIATOR! Then let the engine run to see if the air has escaped. You may have to do this procedure more than once. If at any time you feel that the engine is getting too hot, tighten the radiator cap and then shut the engine off. Then let it sit and repeat the steps above. Constantly monitor your temperature gauge at all times.

try replace cooling sensor

torque converter clutch is bad unplug square plug on front side of trans it will work fine without it

check the temp control switch in the dash

get a couple bottles of gas line antifreeze .. if you don't already use it and add it to the gas.

Robert

P.S. in minus 40 i don't even get out of bed... minus 23 here last nite... isn't winter grand