rpm gauge drops to zero then car stalls
11-14-2010, 08:54 PM
I have a 1997 chevy malibu3.1 v6 engine it started acting up about a week ago. I would notice the rpm gauge would drop to zero then the car would stall. The car will start right up but would shut right down again if the rpm reading is zero even if I it gave it gas the needle would not move. It happens every now and then rpm would start to work and the car would run fine for the rest of the day. I did some research on the web and ended up buying a 7x ckp and bought a used icm from the junk yard and changed the spark plugs while I was at it. Thought I fixed the problem then it started doing the same thing rpm drop engine stall but started right up. This time the check engine ligjt went on and stood on. The rpm gauge stood at zero which gave me time to drive to auto zone and get the scanner up to it. The code was ckp but I told the guy I changed one already he said it could be the wiring. So with some one in the car and the car running I started moving wires at the icm to see if the rpm gauge would work nothjing happened. Next I started tugging the wires that go to the 24x crankshaft sensor the the engine started reving up and down and the rpm gauge started working. Well the wires are in a tight spot I was able to disconnect the harness and reconnect it the cars rpm started working properly and check engine light went out. I'm thinking that when I changed the water pump a week ago something probably got wet with antifreeze or the wires are old and brittle. If it does it again I will change the crankshaft sensor that's behind crankshaft pulley and check the wiring for damage.
12-19-2010, 11:20 AM
Had similar problem with neon that took hours to find, and no code scanner would help. The factory wiring that passed around the back of the head was a tight fit. It had worn through the insulation, and would make contact whenever it felt like it, making it almost impossible to find.