Starting Problem + Tach goes to 0 but car runs just fine
Car would not start although engine cranked after using at night in stop and go traffic. Left alone for an hour or so and then started right up. Ran fine the next day, however, after parking at night wanted to move car to another spot and had same cranking problem. Next day ran just fine. I thought starting problem could be electrical because the nights were much colder than NJ. Drove from Boston to New Jersey, but during first hour of trip exprienced sudden engine surge and Tachometer went to 0. Engine kept running with no loss of power. Nest day when I took to dealer Tach was working normally. Left car for three days. They could not find any problems but thought it maybe the computer. Dealer suggested I hold up on computer replacement until symptom repeated. Today took a 30 mile trip without a problem. On returning home again experienced brief engine surge and Tach went to 0 but car still running OK. Got home, had lunch and started car. TACH WORKING!! Ran a short errand without a problem.
Does anyone know how the Tach senses the engine RPMs? Does it come from the computer? Any idea if the starting problem and the Tach problem are related?
Thanks for any help I cane get. The Customer service guy was not sure how Tach gets RPMs.