im new here so let me start off by saying hello. now my problem... i have a 88 turbo coupe 2.3 liter turbo/5 speed. the car runs well but lacks mid to upper power. it pulls hard untill about 3,500 rpms and then it just seems to flatten out. it will still get to 5,500-6,000 rpms it just takes a lot longer than it should. i have checked for trouble codes and there are not any. i did both the koeo and the koer tests. the timming is exactly were it should be(10 degrees btdc) i replaced the spark plugs with new motorcraft plugs, wires, cap, rotor, throttle possition sensor, all new high flow exhaust, air filter, tested fuel pressure and replaced filter, plus a few more things too. a few days ago i was cleaning out the throttle body with some brake cleaner, when i got it back together and took it for a drive it got up to 6,000 rpms fast and ran fast. this lasted about 20 minutes. then it started to flaten out again. just for kicks i sprayed some more brake cleaner into the throttle body and once again it ran hard and fast for about 15 minutes. could the brake cleaner be fooling a sensor?? if so, which one? i dont understand this. the car doesnt miss, it just flattens out at higher rpms. can anyone help me with this problem?? i would be very thankfull. i see a lot of these turbo coupes destroyed, beat up and abused. i want to try to save this one!