93 toyota T 100 running rough?

This was an intermittent problem, now its steady , I tried easy stuff new plugs new wires , rotor, distributor cap, today I went deeper and did compression test V-6 3.0 EFI engine, I did it twice cause the second time I had a high quality tester , second test results range from 148 psi to 161 psi, I did this cause this truck has 334,000 miles on it. I think the compression is ok, but I don't have a book to look up min. and max now I'm thinking an injector, but I'm scratching my head, no check engine lite came on, ever but It does come on when I turn the key to the on position, so I know I have a lite.I took each spark plug wire off at a time to try to narrow down the cylinder with the problem, two of the wires, when removed do not seem to change the idle, but what else can it be I also tried removing and cleaning the air filter but it really wasn't so dirty. Any Ideas where to go next from you full time motor heads, any suggestions of other things to look for would be greatly appreciated, it takes all its got to climb a small hill spark seems strong at each cylinder Thanks G.