Stumbles after coming to a stop.
I have a 95 Bonneville, with a 3.8L Series II Non Sc. The problem is that sometimes while im driving, doesnt matter the speed, its when i come to a stop that causes the trouble. long story short, when ever i come to a complete stop, only when the car is in the gear, it stumbles as if it wants to die out but it doesnt, the oil pressure gauge flucuates back and forth as well as the voltage gauge. if u can see in the picture below on the oil gauge, the black arrow shows where the hand sits at while driving and at idle. The red arrow shows where it jumps back and forth to when the stumbling starts. And to add to that you hear a pinging sound coming through the exhaust pipe. Before you start to reply, let me mention that the Bonne runs fine on take off, acceleration, and at idle WITH THE CAR IN PARK, no misfires, no leaks, not burning oil at all. Its jus the stumbling after coming to a stop. Another way to describe it is, it feels like the car wants to slightly take off, jerking a little like, "Doum.......doum..doum......doum......doum" and every time it does that you get the pinging through the tail pipe. NOT BACK FIRING ! Changed plugs and wires and coils. Had codes pulled, only code it show is the knock sensor, nothing major. any suggestions ? hope the picture can be seen !!