1993 Pickup Stumbling

[soulwave1]

My truck feels like its got the hickups.At idle(except when cold) the idle speed changes irregularly from really low to perfect to high and back in no certain pattern.At speed its like the engine will intermittently get no fuel just momentarily and cause the truck to "stumble" then quickly catch itself and sort of jerk. It does it quite persitently and is a real bummer to drive(but it never dies out tottaly). I thought about moisture in the tank so added some water eater stuff and also injector cleaner. Its the Ka24E motor, 4 cyl., 4x4,A/C,multi point fuel injected.170000 miles.I checked the codes and the computer reads normal.I changed the fuel filter. It was overdue but problem still the same.recent tune up(plugs,dist cap/rotor,air filter,oil.). i checked fuel flow out of the filter and it looked stedy and strong. Any suggestions greatly appreciated.Thank you.

[zanegrey]

with no codes ,
i suggest you remove the gas tank and clean it out.
and make sure you clean and clear the pickup..

[1volfan]

Does it happen all the time or when it rains?does it do it with a full tank?