Cant find the coolant sensor

sounds like a weak spark. check the ignition control module on the distributor

Sounds like your coolant temp sensor went bad, it is in or around gooseneck /intake area 2 wire plug yellow/brown if I remember right this regulates fuel according to temperature so basiclly it tells ecm how much fuel to send to throttle body for how cold it is out. these go bad and cause a -40 *F which pours raw fuel down intake thus flooding,

I would be considering testing/replacing engine coolant temperature sensor. A faulty sensor can send signal that engine is already warm when it is still cold, thus, less fuel delivery than needed at time of engine being cold.

I'm assuming the engine cranks with the starter but does not start and run.

check the operation of the cold start injector. This is a separate fuel injector that injects fuel into the intake manifold to help richen up the mixture for cold starts. It operates on a timer that is linked to a sensor that measures engine coolant temperature. Once warm or the timer runs out, the cold start injector is turned off. Other things to check:

Fuel pressure too high (floods engine through cold start injector), engine coolant temp sensor or intake air temp sensor is stuck at full hot (doesn't allow enough fuel for cold starts), fuel injectors are leaking (floods engine with fuel).

Are you getting a check engine light? It could be one of the sensors or the fuel pressure regulator. Example: If the coolant sensor is bad and it's tell the computer that engine is cold, the computer will richen the fuel mixture. The O2 sensor sniffs the exhaust if it doesn't like what it smells it might richen the mixture and so on. If the fuel pressure regulator is bad the engine will usually be flooded when you go to start it "hot". Does it start hard when hot, do you have to hold the gas pedal down to get it started when it's hot? If so, it's most likely the fuel pressure regulator. I'm assuming the truck is in good tune, clean air cleaner, spark plugs are good, stuff like that.

If you are referring to the temp sensor at the intake or the oxygen sensor at the exhaust, it may cause it to flood. There could be several causes. But usually the problem may be traced to the MAP sensor or to the injectors. If the sensors are the issue the mixture would either be rich or lean. If the flooding is that bad I would check first the injectors. Have it cleaned out first and do a physical inspection on the parts.

remove your exhaust and see if it runs ok if so cad. converters on exhaust are clogged and need replaced

I had the same problem with my 1990 chevy 1500 (350) replaced the plugs and wires no luck. I replaced the fuel pressure regulator, still no luck. So i called my mechanic he said it would either be the map sensore or the coolant temp sensor. I didnt figure the coolant temp sensor would cause my truck to flood but it was a 17 dollar part so i gave it a shot, took 10 seconds to switch it out with a 19mil deep socket. Truck fired up and ran like a top no more flooding. =)

Change the thermostat for the heating problems. As for the hard to start when hot, check your air filter. Change your fuel filter and check the fuel pressure. Check your engine ground connection. Check the connections in your ignition system. Change your idle control sensor. Could be any one or combination of the above.

After cleaning the fuel off of the plugs and getting them dry try unplugging the coolant temp sensor and jumping the connector (harness side) with a paper clip. This will cause the computer to think that the engine is already warmed up and will not richen up the system. If this fixes the problem replace the coolant temp sensor.