Mechanics

CHEVY MAP SENSOR

1994 Chevrolet S-10

Engine Performance problem
1994 Chevy S-10 6 cyl Two Wheel Drive Automatic 165000 miles

my truck is a CMFI fuel system. I got this truck from my brother and it has always run poorly (low power). My question is would a map sensor vlotage reading of 3.8v at idle be causing my computer to think it has low vacuum?Or be causing it to run weak. A vacuum test shows a steady 18.5psi acceleration test normal.
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Jmichael8888
December 3, 2008.




Ok the voltage for map sensor should be 1 to 2 volts at idle and at wide open throttle it should be 4 to 4.8 volts. So if it is showing 3.8 volts at idle then it would think it is at wide open throttle and give more fuel which would give you poor mileage and poor performance.

Racefan966
Dec 3, 2008.


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