91 sl w/dohc help!!!!

[snakeyez]

i gotta 91 sl2 w/dohc and a whopping 189,000 miles. its never really gave any trouble till now......no spark on the middle two cylinders. runs awful now. (expected) i replaced the 1 coil that the 2 plug wires that arent firing go to and it still dont spark and it runs on 2 cyl... what can this be? i hope not a bad computer.. i checked spark at the end of the plug wires..soo who knows whats up? any body have this trouble. it ran kinda rough to begin with but now its like no power at all 50 is max speed and 3000 is max rpm. my brother was running it a little hard when it happened. i need this car to get to work.....help!!!!!!

thanks