Map Sensor Problem?

Hello everybody i am having an issue on my 1987 fiero gt. Im showing a code error for Codes 33 +34 which both pertain to the MAP sensor. I replaced the sensor and the car is still running poorly. On cold start ups (the colder the day the worse it is ) the car will die manytimes before im able to drive it. I hear a poping noise around 2k -3k rpm. Also untill the check engine light pops on some 30 sec later the car acts really bogged down before 3k rpm. Once the car is warmed up it seems to run relitivly well. I do not know what the Idle RPM should be but its usally around 1.5k and 2k rpm... i dont know if this problem is related but seems way to high. Please help and send me any suggestions. I replaced the map... checked all the vaccum connections... even checked the O2 sensors.....

Code 33 - Manifold Air Pressure sensor
Check the vacuum hoses from the MAP sensor. Check the electrical connections at the ECM. Replace the MAP sensor.

Code 34 - Manifold Air Pressure sensor
This code will be set when the signal voltage from the MAP sensor is too low. Instead, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery. Replace the MAP sensor.

Since you have replaced the MAP sensor, do more checking on vacuum leaks. Of course the "new" MAP sensor may be bad. Normal idle when warm should be below 1000 RPM