This car has the 2.2 liter engine and an automatic transmission. When the car is put into drive and the gas depressed the acceleration is constantly intermittent. The rpms drop to almost 0 then back to normal then back to 0 again over and over again until the car stalls. The pulsing has a frequency of about 0.5 seconds rpm fine 0.5 seconds stalling. This does not happen if the car is driven in reverse. It accelerates smoothly and properly in reverse just not in drive and it does not seem to matter if the car is in low or normal drive. This problem started a couple of weeks ago and has just started getting worse and worse. Now it does it every time I step on the gas. Any help would be greatly appreciated.