2.5 running rough
I have a GMC S-15 4x4 with a 2.5L engine. I have changed the O2 sensor and timed the thing but it still runs king of rough. Yes, I checked all the vacuum hoses and they are good. I checked the computer for fault codes and I found none. The only thing in question is a vacuum line on the very back of the base of the injector. Someone has plugged it and I cant seem to figure out what it goes to. The manual dosnt help me none. I was thinking that if someone else has one of these motors they could check and see where it runs to. Anyone?
92 S-10 Blazer 4x4 Vortec 4.3
85 S-15 Pickup 4x4 2.5 iron duke