My 93 GMC truck it won't start unless I unplug map sensor vacuum hose when I try it to plug it back up truck turns off its starts like fludding its smells a lot off gas. But with out it it stays runing
Sounds like the result your sensor gives to your ECM is incorrect for the altitude. Fuel system pressures and volume tests should be run and a different sensor must be tried. Basic tune up check and spark parts should be inspected for wear and tracking issues. Sensor codes should be run from the ecm test link connector. Return with results to each of these tests and use A/C Delco parts where available. Since your vehicle exceeds 20 years, consult your maintenance records about tune up and fuel system repairs to date.
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