Nissan Repair: engine stalling, throttle position sensor, air control valve

Question
Hello Von...My '87 pick up (2.4/injector-throttle body)keeps stalling at low & mid rpms...It will run a bit, sometimes a minute or two, or run for ten minutes, then stall out...It will run all day long at high rpm with decent power without missing... It will start right back up after the stall, too...It doesn't do it all the time either, hot or cold engine doesn't matter...I replaced the 2 coils (not the small transister type box attached  to the coil)and it made no difference. The plugs(8), wires, dist. cap & rotor were new not 500 miles ago. The "throttle position switch" is also new..
HELP!!!!
Thank You....AL

Answer
Al,

Check the idle air control valve and clean the throttle body.  Usually, if the throttle position sensor is new, the problem is wiht a gummed up throttle body.  The idle air control valve controls the idle air and if the passage is plugged or gummed up the truck will run fine.  But, it will not idle properly and die often.  But, it starts right back up.  So, clean the throttle body and replace the idle air control valve.