Same thing I observed! I found that the oil was coming from a threaded plug with a 10mm hex head just aft of the shaft that has the spring. I tightened that plug and the leak stopped. However: The P.O. had noticed the same leak, one of many, and brought the car to the local dealer. They replaced the windshield wipers and wrote on the invoice "Oil leak unrepairable - N.C." I actually removed the injection pump and put it on the bench. There I discovered that there is a shaft attached to that plug. It holds a lever that pushes on the rack. When you want to adjust for mixture, in order to get a screwdriver to engage, you must back out that plug so that the lever moves a little away from the screw driver slot. It's easy to forget to tighten the plug again. Also, the pump may leak out of the forward end of the rack. Bosch has a rubber cover there, but it hardens over the years. It's very expensive, like $45 and I used a tip sold at the hardware store for canes. Just test it in oil to see if it is resistant.
