Okay so what I have is a 1988 single cab ranger with a 2.0 block with a 2.3 head with a holley 350 carb. The other day I pulled out in traffic and my throttle cable broke and the truck made a loud bang and just came to a hault in the middle of traffic. I assume i stopped so fast because i was going so slow and i still had it in gear. But anyway i fixed the cable but now if i let out on the clutch too fast and it starts to lug and my gas pedal will move by its self almost like the engine is moving but it will only do this if it's lugging. And when this happens my shifter slaps really hard. Also this morning I noticed I have a new dent in my hood from the inside out where the alternator mount actually hit the hood. And i've never had problems with it hitting before.

Keep it still and in neutral. Rev it and let go, if it bangs (usually when you let go) it is a motor mount. I had this happen in my dodge.

It sucked because I did both mounts (may as well eh) and then the whole drive train had to be fixed piece by piece because all the power was going to the drive train (minus the trans). So be ready to do u-joints and support bearing shortly after.