I have been having a random stutter since about a month after I did my top half rebuild. I figured it was an ignition problem and so I have tried replacing my plugs, wires, cap, and rotor twice each. I have taken the truck to a Toyota certified master technician, and he didn't find the problem either. All he said was to try OEM plugs, wires, cap, and rotor. I have checked the gap at the distributor and tried playing around with more or less gap on that. No help there. The coil tests out okay. Fuel pump was tested by the Toyota tech and he said it was within spec for pressure, though on the weak side of acceptable. I am hoping it isn't an injector going bad, but I was thinking maybe one of them is not always firing. Other than pulling them and sending them in for service, I don't know how to test injectors.

I am at my current frustration limit on this project.
Anyone have any ideas on what could be causing this issue?

Edit: Oh yeah, 1986 4Runner 22rec.