Why does my car make a jerking motion while in drive?

The first thing you do is to have the fault codes checked with a scan tool.

You haven't had vapor lock in over 25 years with fuel injection

What exactly defines bad gas,that never was the cause of
vapor lock

You have to retrieve the codes,diagnose them & come up
with a solution, or stop using it,so a repairs shop is where it
should have been some time ago

Fuel filter clogged and or impurities in the fuel system.faulty or incorrectly gapped spark plugs.Fault in fuel electrical system.Defective spark plug wires. Faulty emission system components.Vacuum leaks at the throttle body intake manifold or vacuum hoses. I would first look at the fuel inline filters it sounds like this is the likely problem.

if it jerks its the rack

The problem could be a clogged air vent in the gas cap, causing a vacuum in the gas tank . The next time this happens, loosen the gas cap and see if the problem goes away. If so, replace the gas cap.

This type of issue requires a test drive by a professional.

Sounds like lean operation. Is the engine light on?

have the fuel pump pressure checked, if you think you have a vapor lock,, and your going to think I'm totally bonkers, But an Old man told me this years ago so I tried it, clip 6 or 7 clothes pins on the rubber section of fuel line, I have no clue how this works or why, But it does

could very well be but without a drive i cannot really say sorry but some things i have to trust the local mechanic as i cannot see or hear it over the internet

This is a common happening, but it is not necessarily a problem. What happens is when you are driving, the transmission is locked and providing as much power to the wheels as possible. When you take your foot off the accelerator, the transmission unlocks and goes into a passive state to prevent bogging down the engine. When you hit the gas again too soon, you feel a "THUMP" which is the transmission going back into the locked position. While this causes no short-term damage, if you do it often enough, it could cause increased wear for the transmission.