I just bought a 1986 Firebird with a 305. I got the trouble codes out of the OBD 1 and they are #32 and #34. Both mention the MAP sensor and or the Pressure Differential sensor as a possible problem. It has a 4bbl carb. on it.
My real problem, that I need an answer to is this, the MAP sensor is not connected to any vac hose, I went to the parts hose and got a long piece of hose, but I can't find a place to plug it into the manifold?? also, theres a skinny, tube type hose thats appears to be coming up from the back of the motor routed under the distributor thats just laying on the manifold (possible tranny kick down?) any advice on where the MAP sensor attaches, or a VAC diagram lay out for this car would be very appreciated. If anyone can help, please send email to peebosauto@gmail.com, or just message me on here.

Many takes

 

Not sure if it will help, but Autozone's site has vacuum diagrams for some cars.

 

I believe the map sensor hose comes directly under the air filter housing, follow the v.a.c motor vacuum tube (on your air cleaner duct) and the plug should be directly to the left.