Dear Doctor: My 1995 Nissan Maxima V6 has 210,000 miles and most of the time it runs beautifully. Out of the blue it will start to lose power and idle irregularly. It starts revving up and bucking and then slowing down. The speedometer needle fluctuates until the car finally stalls out. It will run great for days and then this happens. Here’s what has been done so far: replaced spark plugs, throttle cleaned, fuel pump replaced, two fuel injectors replaced, valves replaced and tried using a tank of high-test gas and an additive for the injectors. Please help! Bill
Dear Bill: For the engine to stall and the speedometer needle to fluctuate indicates there is an electrical issue somewhere. My first thought would be a poor ground connection. You need to find a AAA-approved shop that uses Identifix professional support, so that working together with other technicians the issue will be solved. The problem could have multiple origins, including a problem connection or faulty crankshaft sensor. On older vehicles we find many connection issues that result in very unusual problems.