senjorb0b

me yet again, what is the difference between the map and the vac sensor and where should each vaccum line from the two sensors go?
thanks
andrew

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87 305 5.0 litre 4 bbl
Black with gray trim almost done being rebuilt

Vader

Seņor,

It's really the same thing. MAP, Vac sensor, Baro sensor, differential pressure sensor, yada, yada....

The difference is in the application, but the function is similar. Typically you'll find the sensor mounted to the firewall on a carbed engine vehicle. The BARO sensor is on the right side near the HVAC enclosure, and teh MAP is near the brake booster. The BARO sensor has no vacuum line to it, while the MAP sensor does.

Did you look for the label on the underside of the hood? They are often pasted there instead of on the radiator support. Clean up the dust and you might be surprised.

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Later,
Vader
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"Let the bodies hit the floor!"
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Ed Maher

I saw your email but i didn't get a chance to reply yet. Like i said in the original post, a VAC sensor has the opposite function of a MAP sensor. high vacuum = high output voltage on a VAC sensor, low vacuum = low voltage. A MAP is the opposite. High vacuum = low manifold pressure = low voltage. Low vacuum = high manifold pressure = high voltage.

If you put a MAP sensor on a CCCS car you will have a really ****ty idle from teh lack of advance fed it since the ECM thinks you are under heavy load. At high load you'll most likely ping to death cuz the ECM will add timing thinking you aren't under load.

oh yeah, i think in your email you asked what CCCS stood for...Computer Controlled Carburetor System.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

senjorb0b

thanks for the info, but should there be a map and a vac because they are both in the camaro i have? we are just trying to put everything back together because we redid the motor and this is one of the few problems we are having.


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87 305 5.0 litre 4 bbl
Black with gray trim almost done being rebuilt

Ed Maher

There is a 'MAP' sensor in CCCS cars, but we call it a BARO sensor. Exactly the same as a MAP, except nothing is hooked to the vacuum port, thus it is measuring BAROmetric pressure...