I have a 1991 chevy 1500 4.3L, it's failing the inspection for to much unburnt fuel. I replaced the ECT and it's still seems to be dumping to much fuel. smokes at start up and smells rich at idle. when i whent to go have the emissions done it's failing. I really dont want to just start throwing parts at it. what ever the problem is when it trips a code the light will only stay on for about 30sec even while driving down the road. Any idea at this point is good. post your thoughts i need to get this done ASAP. please help me im lost.