vacuum readings over 60Hg...what's broken?
05-06-2003, 06:48 AM
#1
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vacuum readings over 60Hg...what's broken?
Lately at idle or cruising speed my boost gauge registers a vacuum reading over 60Hg. Decrease in performance accompanied this. Vac lines appear to be fine. Is this a sign of a bad throttle body? What causes them to fail? Can I troubleshoot a TB?
05-06-2003, 09:33 AM
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60cm of Hg you mean. Your map sensor sounds broken....
at startup the vac level should drop to about 31cm of Hg then work it's way back up to about 41cm of Hg as car warms up.
05-06-2003, 09:53 AM
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Well, if the sensor is outputting gibberish then ecu will miscalculate the air mass entering...
the engine. It will likely adjust the other parameters, like fuel, timing advance/retard according to what it senses from the map sensor.
Call one of your friends over and swap your map sensor with his and see if it fixes the problem.
Call one of your friends over and swap your map sensor with his and see if it fixes the problem.
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05-06-2003, 09:57 AM
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manifold absolute pressure (MAP) sensor. One end of the sensor element is referenced to
absolute vacuum and the other side open to the atmosphere or to the manifold in this case.