Nissan Repair: engine miss firing, correct fuel, navara

Question
Hi
I have a navara twincab pickup. my problem is that when the engine is cold it runs fine. When it starts to warm up and i accelerate hard or run lower speed in high gear the engines starts to splutter and misfire. any help would be appreciated

Answer
Mark,

If the engine lugs shift into a lower gear.  Also, if the truck sputters you might get new plugs, a fuel filter and cap and rotor to make sure you are getting the correct fuel and spark to run the engine.  Nut, remember that you do not want to lug the engine in a higher gear.  So, when the engine bucks downshift.