MAP sensor.. is it needed

[snodgrass]

I have a wrecked 87 Gn that I'm using for the drive train to put in my el camino. The GN has a digital dash, and their is no MAP sensor on that car. It has a boost pressure switch. My buddy's GN has a analog dash , and his car has a MAP sensor without the boost switch. Since I am using the chevy dash without any boost guage or light in the dash, do I need the MAP and/or boost switch anymore? Does the MAP sensor or boost switch have any effect on timing or fuel enrichment? (I do have a mechanical guage to monitor boost, so I'm not clueless). Thanks for any info, Jeff

 

[ijames]

No, the map sensor is only for the dash boost gauge. The ecm doesn't know it's there or not.

 

[snodgrass]

How does the ECM regulate boost? How does it know how moch boost the engine is running at?

 

[ijames]

It doesn't regulate boost and it doesn't know how much boost there is. It measures the incoming airflow with the maf sensor (which pegs somewhere in the mid-12's), and pulses the wastegate solenoid to raise the boost over the mechanical setpoint, but it never knows just what boost was achieved.

 

[snodgrass]

Doesn't sound like that would work very well, but I guess it's good enough. Thanks for the reply!!!!