I am having a really difficult time with my 1986 Mercedes 190e...

I added the Injector Cleaner and about 7 gallons new premium gas, and drove about two miles, everything okay.

Then I go to start the car hours later, and boom...

rough start, misfires, car barely staying on.

finally i felt comfortable enough to drive home and the car would idle okay enough, so I headed home with about a 5-8 minute drive or like 3 miles... the car ran, but very choppy.

arrived home, turned the car off after a rough ride back. Started the car again, it fired right up, everything great. So I ran the car about 4 miles, just to try and blow anything out that may be causing problems. It ran great, just like normal.

Then, arrived home, turn car off, try and start again.. and Misfires again.

This is after about a thousand dollars of work already on the suspension. Why does this car hate me? What should I do? PLEASE HELP!