Comment by mulmen

My first car would diesel after turning it off. Basically the engine would keep running on fuel in the carburetor and residual heat in the engine. Sometimes it would do this backwards. This was very problematic because the timing belt tensioner only worked in one direction. When it ran backwards the timing belt would jump a tooth then the car would not start. I got in the habit of just killing the motor with my foot on the brake and the car in gear then letting the clutch out.

I also had the machine shop at my high school weld up a custom tool to help me reset the timing belt in a parking lot with a couple of hand tools. It could be done in a few minutes.

This is a long way of saying yes, if they slip it is bad.