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 run
1 Answer
Sounds like the sensor gives an indication of the wrong value. The ecm wants a voltage within the specified range. Trying a known good part is customary. Checking your fuel system pressure and volume and spark delivery parts is indicated as well as basic tune-up parts inspection. The sensors in the engine can be inspected one by one and their indications are customarily checked by a chevy tech during a diagnosis of this type. you should use A/C Delco parts to avoid any variables created by the "quality" of parts in the aftermarket. Your system prechecks also include a system code check at the ALDL connector below the instrument panel. and observing the check engine light or service engine soon light. The chilton/haynes manual available at the parts store or public library can be very useful in helping with what to expect and inspect. Return with your results to these tests and inspections and your help can be arrived at more easily.