The car does not accelerate well. I had the car tuned up - still same problem. In my garagetoday while car was in Park, I pressed the pedal and held it steady - the RPMs dropped, then climbed back up, then fell off again, all while I held the pedal steady. Any thoughts?

Hi, I recommend you check the fuel pressure regulator for a torn diaphram. The vacuum reduces fuel pressure when the engine is not in high fuel demand. However, since the intake manifold is the source of vacuum for these type regulators, when the diaphram tears, it allows fuel to be sucked through the regulator directly into the intake manifold, thus causing a rich fuel/air ratio. To check a regulator on the rail, pull the vacuum hose off the regulator and plug the hose with a golf tee. Start the engine and watch for fuel to come out of the regulator vacuum port. If fuel comes out, replace the regulator. A diagram showing your regulator is pasted in below. If this is not the problem, please get back to me.