whats a map sensor and how hard is it to replace?

 

MAP sensor is your manifold absolute pressure sensor, pretty much speed density. it pretty much calculates air density and determine the engine's air mass flow rate, which in turn determines the required fuel metering for optimum combustion. For example if you unplug that connector hooked up to your MAP the car will die. Once you hook it back up, it will run again, the car cant run without this sensor. And its not hard at all, its just 2 bolts holding it up that you unscrew and unplug the sensor connector to it. Simple as that.

 

A MAP (Manifold Absolute Pressure)sensor is used to measure vacuum so that the ECM (along with other sensor information and pre-programmed constants in the PROM) can approximate how much air the motor is taking in so it can figure out how much fuel to inject to maintain the proper A/F ration on whats called a "speed density" fuel injection system. Its a real easy thing to replace and fairly cheap as well.

 

how cheap is fairly cheap?? i found a deal on a 91 Z for 1300 obo and he says it needs a new one.

 

Well i dont want to quote you as it will very from place to place but ide say like $40. Although then again thats just what he says is wrong with it which obviously may not be true and more often than not isnt.

 

what else could be the problem?

 

Well being that i dont even know what the problem is i wouldn't even be able to begin to guess whats causing it and even if i had a guess it wouldn't mean anything more than just a random shot in the dark without being able to do any troubleshooting to support that guess. However assuming it was a MAP related problem it could be anything from a broken wire, a broken vacuum line, a bad connection, a whole multitude of things other than the sensor itself. Not that im saying its a big deal its just from experience with buying a used car ever problem is something minor like a sensor. Some are just lying to cover up a larger problem but most just don't know any better as lets face it unless there a mechanic or a die hard do it yourselfer thats already done the troubleshooting and done it correctly how would they know? They dont they just guess. Honestly if it was just a MAP sensor seeing as how its a pretty cheap part and easy to replace wouldnt u replace it if you were trying to sell the car to get the car into the best shape possible? I mean if they knew for sure it was the MAP sensor the only way they could know for sure is if they did the troubleshooting and if they trouble shot it they must know enough about cars to be able to work on them. So again why would they even take the time to troubleshoot it and then just not fix it again especially considering its so cheap and easy to fix for someone who knows how to work on cars? Again it comes back to they probably didn't actually trouble shoot it they really have no clue whats wrong really and are just making a guess which from my experience is wrong 90% of the time. It most likely no big deal but again don't count on what the seller says.