95 jimmy misfire on

[A42GO]

My ’95 GMC Jimmy 4.3 w has a misfire that just began on cylinder number 4 (middle cylinder pass. side). I’ve replaced rotor, cap, wires and AC Delco Platinum plugs, and it still has the misfire. Could this be a worn distributor bushing causing too much gap in the distributor cap keeping the cylinder from firing? I have pulled the plug and it’s wet with fuel but shows no sign of combustion. Please advise if there are other possible causes.

[MT-2500]

Is no 4 cyl getting good hot blue spark to the plug?
Is compression good?
Switch plug and wire with another cylinder and see if miss moves.
And yes check dist shaft bushing.
Any vacuum leaks any place?

[A42GO]

All cylinders are geting good spark now after regapping and checking all plugs/wires for good connections etc. Still have misfire, will check for vaccum leaks. I replaced the fuel injection unit about 2 years ago, do you think it's gone bad already.

[old_master]

Check fuel pressure and leakdown. If fuel pressure drops below 55psi after 3 to 5 minutes, the fuel pressure regulator might be leaking. When the regulator leaks, the excess fuel runs into cylinder #4.

[A42GO]

I've installed a new pressure regulator and replaced vacuum lines also did a compression test all cyl test fine 120 except for #4 cyl. is around 100 psi. Could this be a bad intake valve lifter not opening the intake valve. My next step is to pull the valve cover to see whats going on.

[MT-2500]

Just 20 lbs low should not make a dead miss.
A little low could be cylinder miss causing lower compression.
Did you check compression test wet and dry and with TBI cracked open?
Is the plug still wet on that cylinder?

What was the fuel pressure readings?
Why was the fuel pressure regulater replaced?
Did it help fuel pressure?
Is fuel pressure up to par now?
Is it a W or Z engine and PCM or VCM computer?