2.3 Missing at higher RPM, But fine at idle.....HELLP!!!!

[Aschnaub]

I am getting a miss at rpms above around 3K rpm, but only after I left off the accelerator to shift. If you left off it or keep it at a constant low rpm for around 40 sec, it goes away. I am getting a misfire on #2. I changed the fuel injector thinking it was that, no dice. Plugs and wires are new (within 10K). I also changed the valve springs on all valves, and new followers/lifters on cylinders #1#2....soon to be #3 and #4, and it still does it. I cannot figure it out and am having a hell of a time coming up with anything else. Considering either junking the damn motor and rebuilding another or just selling or drive it until it explodes. Has been a great truck, in great running shape and looks excellent for 130K. ANY SUGGESTIONS, I AM OPEN!!!! PLEASE!!!!!

NOTE!
****97 Ranger 2.3L 5spd Manual Dual Plug Head*****

 

[tj4fa]

When you changed out your injectors, were the connectors all green and nasty with corrosion?

It might be the injector pigtails that plug into them if they are corroded.

I have a Maxima that ran rough and after doing just about everything else humanly possible short of washing the engine in gasoline and drying it with a match, I finally cut the FI pigtails off and soldered new ones in.

It ran like new after that (just went over 250K miles).

 

[Aschnaub]

I tell ya what, I may have found the problem but still digging into the issue. I believe i may have carbon buildup on the valves. I took a can of "seafoam" and ran it through the fuel pr regulator vaccum line that goes straight into the intake. it ran a little bit better after the fact and am going to do it again to see if it helps some more. I will also be looking at the pigtail as well because i sure cannot remember what it looked like when i did it. Any more suggestions please throw em out there......otherwise the little dinosaur might get a 5.0 dropped into it and say f**k the rest of it.