Chevrolet Repair: hard starting, chevy lumina, 1993 chevy lumina

Question
My 1993 chevy lumina euro sedan with 3.1 vin code T eng has had a problem with starting when hot. I purchased the car when it had 49,000 miles. it now has 110,000 miles. It had the problem since I purchased it. When the engine is cold like over night there is no problem,it starts right up. But after that first start and for the rest of the day. any time I start it up it cranks but won't start unless I hold the trottle open slightly. Like as if it was flooded. I have changed the computer chip E-prom. this cured the problem of stalling when backing up. But not the hard starting when hot. I have given it Tune ups, Plugs,wires,air filter, fuel filter with no change also replaced the TPS. Don't no what to try next. No problem codes are being set either. Any ideas? Is it a common Problem? Thank you

Answer
Hi John, the first thing you need to do is clean the IAC motor and the throttle bore in front of and behind the the throttle plate. Use a old tooth brush to do this with some carb cleaner. Remove the IAC and clean this too. After your done run the engine in gear at idle for 10 minutes. Then turn off for 30 sec and then restart and run again in gear at idle for 5 minutes.

       Let me know how you make out      Mark