Sorry for the delay. The place to start is by having the diagnostic fault codes read and recorded. The people at many auto parts stores will do that for you for free. Those will indicate the circuit or system that needs further diagnosis.
If there are no fault codes related to this problem, the next step is to have your mechanic connect a scanner to view live data during a test drive. The better scanners have a record feature that allows him to record about five seconds of data when the problem occurs, then he can play that information back slowly later to see what changed. Some sensors provide data to the Engine Computer to base its fuel metering calculations on, and some sensors provide information about what happened as a result. Those sensor readings will help your mechanic figure out where to start.
Monday, July 20th, 2015 AT 7:36 PM
