Hello,
I have a 1990, 2.3 liter, 4 cylinder mustang. I have been having some issues with my car stuttering or bucking for a while now, about 3 or 4 months. I was told it was just moisture in some connections so I let it go. My fluids are all stable except for my gas. I am down to less than 20 miles per gallon and am usually at 24-26. Driving-wise, I have issues taking off, I have to baby it and or it won't catch the next gear at the appropriate time, it will just run up up the RPM's and jerk to the next gear eventually. When I try to get on the highway I'll have get up to about 65 and then my car will slow down and start to stutter. Then thicker than normal smoke comes out the back. Just recently it is even stuttering in lower speeds. I think I may have a problem dealing with gas components in my car, but I don't how to check. Any suggestions?

 

also there is no profuse leaking under my car. Just some small black fluid dots near the rear end of my car.