I got a 94 pickup 5 speed 4wd about 6 months ago and it had a misfire from the start.
Some context:
When I got the truck it had been neglected. Basically no oil in it and the timing chain guides were destroyed. Truck still ran strong regardless. Since getting the truck I’ve done a lot of work to it trying to fix the misfire among other issues.

Actions taken: I’ve replaced the dizzy cap and rotor and put new plugs and wires, fuel filter, replaced the timing chain and guides along with new oil and water pump. Did an Egr delete along with vacuum line delete. Installed Headers with new 02 sensor and cleaned the intake and throttle body as well as the maf sensor. Also cleaned the injectors, New Pcv valve and did a valve adjustment

The truck runs worse after being warmed up and especially worse after each start of the engine within the same day. Worse meaning less power and more prominent misfire.

At idle, pulling the cylinder 2 plug wire has no effect on the engine indicating a dead cylinder but compression tests reads about 165 psi.

I still drive the truck everyday and it when it misfires it can normally be cleared out by being in a higher rpm (above 3k) or by mashing the throttle sometimes.

sorry it’s a long read, I’ve been dealing with this for awhile and am kinda lost at this point lmao please help.

 

It's not too long. By misfire, do you mean rough turning upon acceleration? All gears?

Have you checked the vacuum system? That's what I am investigating now.

 

I just drove 2 hours straight down the highway and it misfires in all gears anything under like 80 percent throttle and the engine runs rough and vibrates and has considerably low power, but it clears up most of the time above 3k rpm ish and/or above 80-90 percent throttle. TPS issue maybe? I’m gonna try and take some videos to help explain the issue