[Greg Reimer 7376]

OK. Without picking up a wrench, this is what I have suspected/deduced:.
A. Oxy sensor doesn't work on anything below a certain temperature. Since this is a cold start issue, it can't be that, since the ECU doesn't receive exhaust temperature data until at least partial warm up.
B.Engine coolant temperature sensor has been replaced. This is the two wire sensor located in front of the thermostat on the intake.If this is disconnected and the engine started it is so rich that it won't even continue running. With it plugged in, it at least runs. Obviously,this has to be working since engine warm up has a fairly fast effect on the rich condition.
C. With the air cleaner off, and the engine running, two fairly distinct cone shaped showers of fuel can easily be seen leaving the injector nozzles and making their way past the throttle blades into the engine. Disconnecting each injector's electrical connector one at a time and reconnecting them results in an equal drop in rpm as the engine receives less fuel.
D. With the engine not running,activating the fuel pump to pressurize the fuel system didn't reveal any injector leakage.
E.All of the above described suggestions and discussion are relevant, I just haven't taken the time to find it yet. I'm sure the catalytic converter that I took off was ruined by cold starts and too much fuel. This truck only ran 2000 miles in the last 4 years since I got it. It runs well and tows strong. I went to Bakersfield two or three years ago towing my open trailer and Chevelle up there, a distance of 150 miles each way,
you all know that that's not exactly an economical flat ride, and got 10 miles per gallon, doing the whole trip on less than one tank of fuel. I'll get it right, and update this thread.