hey guys, i was wondering what exactly does the map sensor do?

 

It measures (by air pressure) the amount of air that goes into the intake manifold. From this, the computer can meter out the appropriate and corresponding amount of fuel through the injectors. This is not the only determining factor for fuel metering. Intake Air Temp is another and there are other parameters as well.

 

oh ok thanks a lot! if the map sensor goes bad, what would it affect?

 

Map, in this case, = Manifold Absolute Pressure, if I'm not mistaken.

As Xviper pointed out, the Map sensor measures the air pressure inside the intake manifold. When the throttle is closed at idle, the pressure is very low because the engine is trying to suck in air through an almost totally closed throttle valve. At full throttle, the air pressure in the intake be something just under outside atmospheric pressure.

The more pressure you have in the intake manifold, the more air you've got flowing through and the more fuel you'll need to maintain a correct mixture. If the map sensor goes bad, it will be feeding incorrect data to the ECU (engine control unit) and the engine will not run properly at best or not at all at worst.

Other parameters that the ECU looks at to calculate the correct mixture (ie: the correct fuel flow) for the engine are:

Air temp, throttle position, and engine rpm.

FWIW!

Drive Safe,
Steve R.

 

You could get any number of symptoms:
-poor or irratic idle.
-hesitation at any or all rpm.
-a "miss" when accelerating moderately or briskly.
Honda has determined that it's not always the sensor itself that goes bad, but it can also be a poor connection in the wiring harness. This is why they have issued a new TSB for the MAP situation. This TSB focusses on the secure attachment of the wiring harness by adding a tiny retainer plate and a zip tie. The MAP sensor is changed but the part number remains the same.

 

What model years does the TSB affect?

 

i have a problem that may seem to be related to those symptoms. how can i check to see if it is the map sensor or something else?

 

Does Honda use any kind of di-electric (sp?) grease in the MAP sensor connection?

Just wondering.

Steve R.

 

Any model year that shows the symptoms. Like I said, the sensor has not changed. It's mostly the securing system they've adopted and so far, no S2000 has this securing system. I'm not sure if new S2000 being manufactured now are getting it.

 

You can't. Take it to your dealer.