Is it the AFM? The Fuel Pump? The TPS? Any help would be greatly appreciated. Thanks!

 

Well lets see? You have a vague description of your stumble. I am hoping that the tune up is all good? cap rotor wires plugs? If so lets go a little further. How is the cold start? does the engine rev up to approx. 1700rpm? If not lets change the auxilary air regulator (located beneath the pcv valve) Second lets take the big hose off the throttle body. Engine off, open throttle wide open spray some carb cleaner in there, and scrub the plate, and body with a small wire brush. spray out all carbon. (carefull not to go crazy with the carb cleaner) You will have to hold the pedal about halfway while cranking it over, it will run like garbage for a minute, but its worth it! 3rd Make sure the tps connector and switch arent corroded. You can buy the connector new from the dealer. Set tps as follows. Tps connector off. engine off. using a volt ohm meter. check for continuity on the bottom two pins at idle. loosen 2 7mm screws to adjust it up or down. 4th Have you ever changed the head temp sensor? They usually corrode and lose there value. Also replace the head temp sensor sub harness. They corrode as well. ( the head tempp sensor is located in the front of the cylinder head, just beneath the distributor. Its a tough one with out the tool) You have to remove the bracket from the a/c. it has the idler pulley on it. 2 12mm bolts and 1 14mm bolt. You will see a small harness coming from the head. it connects to another connector thats secured to the timing belt cover. I know it sounds like a lot. but believe me its worth it if the car has high mileage. I have been working for nissan for 17 years, so if you have any more questions feel free to type away!! Good luck!! Those tips really really work well!!