98 sunfire map sensor problem?

I have a 98 sunfire and I jusr recently replaced the engine seeing as the other one got hot and locked up. Now that I changed the engine roughs really rough and when u press on the gas cant get passed 2500 to 3000rpmin gear or in park or neutral. Tested both map sensors from both engines changed throttle bodies changed plugs twice and they keep fouling out. When u hook up the computer scanner it reads really high on map but when u test with a pressure gauge it works. All vacum lines r hooked up to the best of my knowledge. Any ideas please please let me know......

If it's reading real high, that means there is a vac leak somewhere......

It is reading high but what seems to be the problem is that its running really rich dand keeps fouling plugs. Changed the injectors from my engine changed throttle body changed crank sensor changed ignition contol module took a pcm from a 98 cavalier pluggd in no change relearnd crank sensor new plugs. Running out of options any help would be great.

First of all, the PCM has a built in rev limiter, so you are not going over 3000 rpms in P or N.....

What are you getting for a MAP reading, key on, engine off? Should be close to 5 volts.....

With engine running, the MAP voltage should drop dramatically due to high vacuum.....what are you getting?

What are your rpms at idle, engine cold? When the engine is at normal operating temp?

If MAP readings are high, this will cause the engine to run richer.....

The rpms at idle are around 680. Map is reading around 2.3v running and it said 15 17 for inhg if not more didnt check with engine off only with engine on to be honest. unfortunately the car is not near me now to check. I know there r three vacum hookups on the back of throttle body one to the emission one to the regulator on rail and ome to this plastic tube in wiring harness that goes to another hookup by master cylinder.