2000 neon stalling and stumble

I have a 2000 neon 2.0L sohc.. and I have a problem that I cant seem to
figure out.

When it is hot outside.. usually above 28 degrees, my neon has a huge power
loss and at hiway speeds, with the throttle held steady, I can feel a
stumble about every 15 - 20 second.. Also if I come to a stop and idle for
more than 30 seconds, the engine idle seems drop a bit and then it just
quits.. It alway starts right up again, and only happends when it is hot
out. MAP and TPS have been changed... Any ideas? I thought coolant temp
sensor but I just dont know!";

 

when was last tune up? plugs and wires. also have the coil checked they fail
in high heat.

then has your throttle body ever been cleaned.
crank case matter can foul up the TB on the back side and orifices.as well
as the idle control motor................clean and inspect.

if not any of that I would start checking wire harness and plugs for green
corrosion on the contacts.