Before 1988 Jettas/Golfs/GTI's used a fuel 'injection' system had that a pump located at the front passenger side of the engine bay, with 4 hoses (with metal braid on the outside) to carry the fuel to each cylinder. It was called the Continuous Injection System (CIS). Beginning in 1988 VW used the Digifant II system for the 8 valve engines (except for some cars in California which had the Digifant I system).
And before you replace the throttle cable (or accelerator cable, same thing) be sure to check that it hasnt simply come off the top end of the gas pedal pivot. The gas pedal is a long lever that is pivoted in the middle. When the bottom (pedal) end is pushed down, the top end moves outward, bringing the accelerator cable with it. Maybe the little metal pin in the pivot has come out. You can see that by shining a flashlight up from the gas pedal to the top of its lever. Reaching under there may be a stretch, as its not spacious.
I still owe you that info on what is in the picture.