Are all map sensors the same from TBI and cc carb? I looked at the numbers and they are different but the vac connection is the same and the wire colors and connections are the same. Would a MAP sensor from a TBI 350 work in place of a cc carb 305? Mine's bad and I don't want to buy a new one because I'm going to change it all out next spring. I just need something to get by for now till spring.

 

The MAP sensors will behave the same on TBI and CCC applications. This comes with a couple of caveats. First, the MAP sensors have to have the same range. Swapping a 1-bar MAP with a 2-bar MAP is definitely going to cause problems. Second, make sure you really have a MAP sensor (i.e. manifold pressure) not a Vacuum sensor (i.e. manifold vacuum). Some CCC carb applications came with this vacuum sensor. I'm not sure if the connectors for MAP vs. vacuum are identical or not. I do know the computer won't like it if you mix them up!!

 

How do you tell a 1 bar from a 2 bar? The one on my carb engine is hooked up to the back of the carb and the one on the TBI engine is also hooked to the back of the throttle body, they both have the same number and color wires. My repair manual calls it a MAP sensor and says "also refered to as a vacuum sensor".

 

i think thats the barometric sensor.(senses outside air pressure) at least it lookes like the one my 91 rs had and when it was disconected it didnt start well. it should have a big vaccum line going to it, this line is a main vaccum line from the throttle body.but hey i could be wrong. but the map sensor i believe plugs into the air cleaner assembly on the carbed and tbi engines. on the tpi models it plugs into the plenem and they have a conector with 2 wires i believe going to them. the map sensors are about 2 inches tall or so.

 

The baro sensor is mounted on the passenger side by the heater box and doesn't have a line going to it.

 

thats where it was on my rs aswell. i thought it possible that it may be different for other cars. i was going off the look of it since i have never owned a carbed car. sorry i wasnt more helpful.

 

Trust me , that's not the only thing that is different about this car. When I first seen it before I got it, I didn't even know they put carbs on IROC Z cars. After I got it and started getting it running (it had set up for about 2 or 3 years) I started finding all kinds of stuff different than what I knew. I had a bad cooling fan relay. The PO had twisted all the wires together going to the relay so the fan would run constantly thus burning up a 4 wire connector over by the heater box (and the fan motor) . I first had trouble finding the correct relay because mine has a 5 wire plug but only using 4 wires going to it, every one I found was a five wire relay. I had to get a five wire plug from the junk yard and re-wire it with the correct size wires to connect back to my harness. I never did find a four wire connector to replace the burned one by the heater box so I had to but splice the wires together. But slowly I got the bugs worked out. I'm planning on rebuilding the engine and changing it to a TPI setup next spring, if the creek don't rize and he!! don't freeze over.

 

You'd have to check part numbers or test the sensor itself to know whether you have a 1-bar or 2-bar sensor. Here's a link that gives a little more description (and part numbers) : GM sensor information

 

Thanks for the link. At least now I have something to help me look when I go to the junkyard.