Lexus Repair: 93 gs300 cold start problem, air flow meter, coolant temp

Question
I have a 93 gs300,200k,runs great,but we live in wisconsin and it has been below 20 to -15 degrees lately.car will not start,tried new battery,nothing.when above 20 degrees it is hard to start,i have to press on gas pedal a few times and it runs real rough briefly and also black smoke comes out of pipes for a few minutes,it eventually clears up but when going in town it seems that lights get dim a little if i am not revving the car up more.any ideas?right now car is in my cold garage -4 degrees outside,wont start, i smell fuel after trying to pump it,so i assume its getting fuel.HELP! THANKS

Answer
it seems to me that you've made sure of having a good battery source. with temps below 0 degrees, even a good battery will be affected. so its good that you have a good one. next it sounds like the plugs are fouled with fuel. remove them and inspect. they are probably soaked with fuel. replace them if so. using the throttle does not really effect the starting of the motor greatly. due to the fact that its fuel injected. the computer determines the amount of fuel needed by sensors located on the engine. the two main sensors involved with enrichment is the coolant temp sensor and ait temp sensor. another sensor that is important also is the air flow meter. once the plugs have been replaced see how the motor runs. if you continue to have starting issues when cold. you may have a engine control problem. this you will probably need a technician to do some diagnostics to determine why its getting to much fuel. one of the above sensors i mentioned may be out of range. which in turn could be causing unwanted fuel enrichment.
good luck.