I own a 1995 Dodge Dakota V-6 PU with just over 97,000 miles on it. My son had it tuned-up two years and 10,000 miles ago. The prior tune-up was done about 3 years before that and included new plugs, plug wires and distributor cap. For the past 3 months the engine has been racing–up to 3000 rpm’s when you start to accelerate. It reverts back to 2000 rpm’s only when you take your foot off the accelerator, but once you again begin to accelerate it speeds up again which is annoying in standard city traffic. Any one out there have any ideas on what could be causing the problem and how it could be corrected? At this point, I’m not willing to invest much money in correcting the problem. Any help would be appreciated. Thanx
One thing that can cause this is an engine vacuum leak. If extra air is being drawn into the engine, the O2 sensor detects this, and the computer will then add extra fuel in an attempt to keep the air/fuel ratio correct. When you step on the accelerator, there’s even more air and fuel being added and the RPM’s will rise even higher.
Remove the intake duct from the throttle body. With the engine idling, block off the throttle body inlet. If the engine speed slows down but the engine continues to run, there’s a vacuum leak somewhere on the engine.