Shakes or Wobbles problem
1987 Other Volkswagen Models 4 cyl Front Wheel Drive Manual 120000 miles

Hi, my fox is causing me grief. It will run great in the morning and then later in the date will suddenly start shaking and hesitating, then after driving a few miles, will start to stall and shake, stall and then not start altogether.
We first replaced the fuel pump & filter. Then the problem went away for a week or so. Then a few days later, same thing happened. We checked the gas pressure and spark, cleaned the distributor, and it runs good for a few miles and then same thing again. This time I added about a half tank of fuel and a bottle of gasline antifreeze and it ran perfect for about a 100 miles. Now it is at a 1/4 tank and it is hesitating again.

It seems everytime we release the gas pressure it will start and run well for a while. I thought it might be water in the tank because the problem worsens as I get lower in the tank, but I just added a 2nd bottle of gasline antifreeze and it doesn't seem to be working any better. Maybe the injectors are dirty? Any ideas?