1993 chevrolet 5.7 efi map sensor readings

1993 CHEVROLET SILVERADO
200,000 MILES
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RESTOREIT
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Getting 5 volts from a to c wire and 4.7 from a to be. chiltons says reading fron a to b shoul be .5 volts. Please help with proper check procedures and if i have wron readings help on what to do.
Jan 13, 2012 at 9:30 PM
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HMAC300
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give us the code next time. see attached pics. But before you do that if your hose going to the map sensor is soft then replace it as this is a lot of the problems. also check the tbi gasket for leaking causing a vacuum leak, use choke cleaner to srpay around it if the rpm change it's leaking. this could cause the same thing. also make sure pcv hose is not soft either and egr isn't opening at idle.
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Jan 14, 2012 at 12:42 AM