motor won't go past 3500rpms

[mtburk1]

I have a 1982 Sport Coupe that runs great. I recently bought a tach because it didn't have one stock. At 3500rpms it stops going and won't go past that rpm. Maybe the tach is wrong but I don't think so, 2200rpms is 65mph. I have had the turbo rebuilt, replaced the plugs, wires, cap, rotor and installed a ARP cone filter. It runs great. I have to let off at 3500 and it will shift and take off again. The check engine light has come since it hit 54000 miles. Could the oxygen sensor be why? Or is it something else?

 

[b4black]

I would start by checking to see if the throttle cable is actually opening the carb up completely. Sometimes the linkages get hung up.

I would also check the TV cable adjustment:
http://www.gnttype.org/techarea/transmission/tvcable.html