"Stumbling" while maintaining speed
 

Hey all, I have a 93 4Runner, 3.0 V6. Truck idles perfectly and runs great...except while maintaining speed between 1500-2500 RPM, it feels as if the truck is "bouncing"... When I accelerate quickly I cannot seem to feel it as much, only on slow acceleration or maintained speed. Replaced plugs, wires,cap and rotor. Have also run two Lucas injector cleaner treatments through. Any advice on what to try next?

does it do it in all gears, or is it at a certain speed that happens to be 1500-2500 rpms? also if you hold it at 2500 rpms out of gear does it do it, or is it only under a load as you described? what did the plugs look like when you changed them?

It does it in all gears as well as when taken out of gear..the plugs I replaced were pretty worn and needed to be replaced...the cap and rotor looked to be in good condition but replaced them anyway. Wondering if it may be a vaccum problem?...pressure regulator?...fuel filter?

Problems with EGR function? Other vacuum leak or problem with mis-routed vacuum lines?

If you still have the vacuum system diagram sticker on the inside of your hood that's an easy reference to check the vacuum system lines being in the correct places.

There's a ton of info on this site for checking EGR functions. The FSM is good for that stuff too.