Ford Repair: FORD RANGER FUEL PROBLEMS, jet performance chip, throttle position sensor

Question
I HAVE A 1989 FORD RANGER 2WD WITH A 2.9 AND AUTO TRANS. I HAVE HAD SOME RECENT PROBLEMS WITH THIS THAT MAY OR MAY NOT BE RELATED TO MY CURRENT PROBLEM. I WAS HAVING FUEL ISSUES WITH THE TRUCK AND I REPLACED THE MAP SENSOR, FUEL PRESS. REGULATOR AND THROTTLE POSITION SENSOR.(ALL FROM JUNKYARD). I FINALLY TRACED IT DOWN TO A BAD JET PERFORMANCE CHIP.I CHANGED OUT THE RADIATOR FOR ONE THAT WAS TWICE THE SIZE AND THE ENGINE SEEMS TO RUN HOTTER THAN BEFORE? I LIVE IN LAS VEGAS AND IT HAS GOTTEN UP TO 105 IN THE LAST FEW DAYS, YESTERDAY THE TRUCK GOT A LITTLE WARM BUT WAS STILL WITHIN THE NORMAL AREA OF THE HEAT GAUGE ( RUNNING ON THE A AND L)THE TRUCK RUNS FINE ON THE FREEWAY BUT WHEN I EXIT AND SIT AT A LIGHT IT STARTS TO ACT LIKE IT IS RUNNING OUT OF GAS. IT THEN STALLS AND WONT RUN AGAIN UNTIL THE TRUCK COMPLETELY COOLS DOWN AND THEN IT RUNS GREAT AGAIN. IM GUESSING ITS FUEL RELATED BUT I COULD BE WRONG.DO YOU THINK THE BAD JET CHIP FRIED MY ECU? OR IS IT JUST A HEAT PROBLEM? THE FUEL PRESS IS 30 LBS AT IDLE AND 35 AT ABOUT 3500 RPM WHEN RUNNING GOOD. THANKS FOR YOUR HELP.  

Answer
Hello Brad,
   First, I would check the thermostat, make sure that it is the proper temperature, and replace it if you have not already. You also could have a fan clutch freewheeling a little too much. Look for fluid residue out of the front hub of the fan clutch.
    I would also recommend not using junkyard parts when possible. I'm sorry it took so long to get back to you, and I hope this info helps. Good Luck   Shaun.