Manual and troubleshooting

there's a pretty good chance you have coolant contamination that's clogging up the flow of the radiator fluid. this would cause unusual strain on the system as it will begin to overheat and the engine may compensate to try to cool it using the thermostat to open the flow of the coolant. but on a cool day, it never needs to.
on a hot day, it's trying to push around gunky coolant and it's not cooling properly, so the engine .. basically sucks to drive.

try having your radiator completely flushed and cleaned out first.

try mass air flow sensor

.dear first . you need to make sure ignition coil on spark plug are ok
second fuel pump . third you should keep engine runing without accelerator for a while then you can accelerated .

Engine ECU is provided with a high RPM ignition cut off. Perhaps that is what is confusing you. When you accelerate at a fast rate, probably you get higher RPM's and the ECU cuts the ignition to protect the engine from damage.

For this types of problem,there are few help inks to troubleshoot the problem.Click the link below to go through the troubleshooting procedure to resolve the issues :----Idles rough and quits when gas pedal is pressed less? http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html-----------van idles rough? http://howtobyme.blogspot.in/2012/01/2004-ford-freestar-van-idles-rough.html
--------------runs lean and idles rough? http://technoanswers.blogspot.in/2012/02/ford-runs-lean-and-idles-rough.html
-----------Car still runs Rough after tune up? http://howtobyme.blogspot.com/2011/12/car-still-runs-rough-after-tune-up.html
------------Idle flair is noticed on car? Rough idle? car will not idle? Erratic idle speed? http://technoanswers.blogspot.in/2012/02/idle-flair-is-noticed-on-car-rough-idle.html
----------High rpm in neutral? Inconsistant high RPM in neutral? http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html
------------Engine Backfires? http://technoanswers.blogspot.in/2012/02/jeep-backfires.html----------- Nissan stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

-----------
Nissan Pathfinder Backfires? http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-backfires.html
---------How to adjust rpm? http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
------------Engine cuts out at 3000 RPM? http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html
----------This will help.Thanks.

The fuel filter needs to replaced first. If the problem persists then next thing is the fuel pump for a replacement.

A lot.
Fuel cut off valve
Wire harness
Pump.
Etc..

idle air control valve is going bad