In the 3 gen camaro's they have a lot of "lost of ground" problems. Try checking for ground wires under hood near the firewall. if you loose the ground the sensors will not work proplary...
ect sensor bad
Coolant temp sensor, or leaky injectors, bad Ecu, weak battery
The 1993 has an extra coolant temp sensor on the rear of the head.
replace the crank shaft sensor cheap and easy
when the temp sensor is faulty the engine wont turn over, replace temp sensor, it is located in the termostat housing, it just plugs into it.
Coolant temp sensor (not the temp sending unit) may be faulty. The year, make, model and engine info would help.
next time it won't restart, try disconnecting temp sensor
Run a compression test. Unfortunately Volvo engines are among the group that are sensitive to overheating. I wouldn't waste any more time on it until you've verified that the compression is up in all cylinders.
check coolant temp sensor
Replace the outside temp sensor. Problem could also be the climate control head. Read other posts about the notorious AC hot/cold problems affecting Intrigues, which has no certain solution. Before spending the money on a new outside temp sensor, if your temp is just reading low, try cleaning your battery terminals where they contact. Remember to remove the Negative first, and reattach it last. The sensor is really sensitive to voltage changes.
Look by the thermostat housing its the one closest to the housing. unplug the wire and use a 13/16 socket to remove. NEVER use teflon tape on electrical components as it could upset the ground to the engine and cause damage tothe circuit or new components, it wont leak.
check the o2 sensor