I have a 86 IROC with comp controlled quad. I have a map sensor mounted on the driverside next to my cooling fan relay (one in first pic). This sensor is wired and plumbed to the back of the carb according to the schematic BUT I also have another map sensor looking thing on the passenger side by the heater box and something mounted on the intake next to the distributor (one in second pic). The sensor is wired up but no vac line going to it. The thing on the intake is wired up also and has two lines hooked up on the front end and a empty port on th rear. Does this plumb to the sensor by the heater box? If not where do both of them go to? and what are they? I have a "map sensor " code on my check engine light and was wondering if this not being hooked up is the cause. But why does it have two?PLEASE HELP!

 

The one by the heater is the barometric presure sensor... it measures the ambient air pressure... it adds precision to the ECM's knowledge of what mixture is required, because that's proportional to the difference between ambient pressure and the pressure inside the intake manifold.

 

where does it hook up to? does it go to the thing mounted on the intake by the distributor or where?

 

Your pcv filter is unhooked.

 

It doesn't hook to anything except the wires.

OBTW the thing nestled down between the valve cover and the carb and the distributor, is the EGR control solenoid.

 

but the thing on the intake has vacuum lines going to the front side and a open port at the rear.The map sensor looking thing has a vacuum port on the bottom that's not connected. If it doesn't connect to anything, how does it do anything? does it just suck air up into it to compare to the air in the intake?

 

The thing on the intake is the EGR solenoid.

One vacuum line supplies vacuum to it. When the ECM commands the EGR to operate, the solenoid opens and sends vacuum through the other port to the EGR valve (large round thing just in front of that, between the carb and the valve cover). The uncovered port is a vent. It allows the vacuum to escape from the EGR valve when the solenoid is not operated. Without the vent, vacuum would just stay there, and the EGR valve would never close.

The thing up on the windshield cowl, with the 3 wire connector, is the baro sensor. The one over by the brake booster is the MAP sensor.

 

Thanks. At least now I know they aren't "disconnected".

 

Might need a vacuum hose to one of them, diagram here:

http://www.fl-thirdgen.org/mrr23/wir...5.0carbvac.jpg

 

thanks. fortunately my car still has that drawing sticker so all that is still hooked up.