93black-ta

what can the symptoms of a bad map sensor be with my speed density lt1? i know i use it more so than the maf cars so it seems a bad sensor or connector would cause more problems than in a maf car in which it only causes bad gas mileage and poor preformance. im asking because my t/a isnt wanting to idle and it started when it threw a code 34.

Injuneer

The MAP sensor is extremeley critical on the speed density cars..... it is used to calculate the density of the incoming air, so the ECM can calculate the mass of air, and then calculate the amount of fuel it needs to add. Without an accurate MAP sensor reading, you will have the wrong amount of fuel being added.

And, it will be difficult for the long term fuel corrections to bring you back to the correct A/F ratio, since the tables for the limits of the long term fuel correction cells are based on RPM and MAP. And, if that's not enough, you will probably have the wrong spark advance, since the spark timing map uses RPM and MAP to figure out the correct spark advance.

DTC 34 indicates the MAP sensor is indicating less than 14kPa at idle, and that will definitely screw up fueling and spark advance.