My car doesn't accelerate when it is heated up

I have nissan sentra 1996 (fb 14). When I
drive car in the morning looks fine. But
when it is getting hot (both car and
atmosphere) randomly it is felt that there is
lack of fuel coming(there is enough fuel).
Then it is getting worse and finally though I
press accelerator car doesn't move
forward. What  I do is stop the car and wait
for 2 -3 minutes  then start the vehicle and
problem gone. I can drive some far until it is
happened again. As I understood it is
happened only when either car or
atmosphere is heated. No check engine
showed up. EFI cleaning, tune up, engine oil
changing, air filter & fuel filter changing
done. What would be the problem? Some
say if alternator coils old with the high temp
would cause this? Please tell me what
should I do?