Nissan Repair: 90 Pathfinder studder on acceleration, throttle position sensor, haynes manual


Question
I have a 90 Pathfinder 3.0 V6 150,000 miles that lately has been "missing" at idle and has a bad studder in acceleration especially around 55-65 miles per hour and worse when in overdrive. I have checked the plugs, cap rotor and wires, haven't done a compression test but have heard it may related to a loose connector on the MAF sensor or a plugged EGR valve or a burnt valve in the valvetrain. Any nissan 3.0 "quirks" that may cause this/ help my troubleshooting? thanks in advance for your help

Answer
Pat,

I would first do a tune up to make sure that the vehicle has fresh plugs, wires, cap and rotor.  Now, if that doe snot do the trick check for error codes.  There is a listing in the recent past I posted on how to get codes off the old computer.  I would get a Haynes Manual and a volt ohm meter to get the procedure for testing the various components.  I would start with the throttle position sensor.  Also, make sure there is no oil on the optics in the distributor because that will cause the vehicle to cut-out.  And, yes the air meter will cause the stumble at idle as well as the miss at speed.  So, there is going to be some diagnostics but isolate each and follow the Haynes and you should be fine.