Ok, did a new plastic vacuum line, disconnected the battery overnight, started right up and then cut right off, 2 times, when the check engine light came on it runs fine at 1K rpm's. Sitting at a light or stopped it will idle down to 800 rpm's and run for a few seconds and then back up to 1K rpm's.
When it idles down to 800, that's a try at closed loop mode, and something is throwing a large enough trouble code to kick it back into 'Open Loop' or 'Limp Home' mode.
When in closed loop, you are working from all the sensors and the engine is trying to do optimum fuel mileage comsumption.
When enough trouble codes flash, or you have one major sensor that isn't working, then the system goes into 'Open Loop',
Which is nothing more than dumping enough fuel for the Engine RPM (Speed) and usually the supply entering the engine (Density/Volume) and the computer can determine how much air is getting in by one of three means,
The O2 sensor, the Throttle Position Sensor (Throttle Angle) or if equipped, the Air Density Sensor that also tells volume of air.
My guess is you have a wire that is disconnected, grounded, isn't making a good connection, or you have a sensor unhooked somewhere,
You are running the sensor wires (Low Voltage) next to something that is causing INDUCTION, creating current in the wires that shouldn't be there.
More problems on swaps crop up from bad grounds,
(people simply WILL NOT run dedicated grounds to the computer, engine block, transmission case, ect. so the computer sees the same electrical potential at all inputs)
Or bundling the sensor wires with high current wires, like wires to the coil, heater motor, or running them too close to things like alternator and coil/spark plug wires.
One knucklehead actually bundled his computer wiring with his speaker wiring for his base speakers!
Car ran fine as long as he didn't turn on the subs,
but as soon as he fired up the 'Rap Crap', the car would do STUPID things!
(I told him it was "God's Way" of telling him he shouldn't listen to 'Gangsta Rap', wear his pants around his knees and his hats on sideways!)
Anyway, make sure your wiring is sorted and shielded for the sensors,
Make sure everything is soldered with SILVER BEARING ELECTRIC SOLDER, not the lead/tin crap off the discount store shelves,
And sort through to see if your sensors are all working (usually done with a multi-meter or laptop with a Calibration Mapping program which you can find on the internet for free now)
Still reads the same codes, a 33 for the A/C and a 14 for the map sensor.
A/C reading, is it an open circuit code, or is there more than one code, like for over limit on the A/C for the donor vehicle?
MAP sensor problems are almost ALWAYS either the MAP sensor it's self,
Or the connector to the map sensor.
Since you did a swap, you might want to check the connecting wiring all the way back to the computer along with checking the physical things at the Sensor it's self...
(Make sure there it's mounted NIPPLE DOWN, make sure there are no 'Low Spots' in the lines leading to the sensor, so vapors can't condense into liquid and plug things up,
I'm figuring an O2 sensor, but I'm not sure yet. I'll find out, going on an 800 mile road trip tomorrow, we shall see. Anyone, ideas?
It will probably make the 800 miles, but my guess is it will have horrible fuel mileage if it does the entire trip in open loop...
One other thing you might want to check,
A clogged converter or smashed pipe will cause high back pressure,
And that will throw a vacuum (MAP) trouble code,
So will a IAC motor not working correctly...