1996 Chevy S-10 cylinder misfiring

I have a 1996 s10 blazer, 6 cyl, 4.3 ltr, 2 wheel drive, automatic, that has sat for about 2 and a half years. I have had some fun trying to get it to start, but after dropping the tank and inspecting the fuel pump I found the inner pump line was falling apart. With a new pump installed I figured my problems were over. Now it's running very rough and the check engine soon light keeps flasing. I put on the code reader and it says 2nd cylinder misfiring detected. I checked my manual for trouble shooting tips and checked the plugs. The #2 plug seemed fine and gapped fine. I then switched the #2 with #4 plug and reread the code reader, same thing, 2nd cylinder misfiring detected. Before I replaced the fuel pump, one of the first things I did was check the fuel injectors and cleaned them. When I reinstalled them the side clip on the #2 poppet broke off. The poppet still pops in but would this be the problem of the misfiring. I have already taken off the air intake plenum about three times and reinstalled so I would like to have your input before I start on my fourth time. Note that the vehicle was started up on a regular basis for the time it sat untill I decided to have it recommissioned. Please, any and all help welcome. THANK'S