89 Ranger runs rough or misfires

89 4 cyl. EFI with 8 plugs, 180k starts and runs well at idle but runs rough or misfires under acceleration or going up hills. I suspect plug wires but can't find one leaking, not even at night.

Also where is the PCV valve on these models, I can't find it..........

Thanks

Footnote: I pulled 3 plugs at random and they all had a nice frosty white apperance, correct gap and no gunk on them. Now I am second guessing the plugwire need ???

If someone was under your hood before this happend I'd make sure your firing order is right and then I would go for new plug wires poss. new plugs because sometimes even good looking ones could be bad.

Solution: New plugs and wires has this old Ranger purring like a kitten. The plugs were still OK but since the wires are such a bugger to put on, (the drivers side) I put everything in new. I had two of the eight wires that were obviously bad.

Still haven't found the elusive PCV valve...........

PCV should be underneath the alternator.