New (to me) Audi

[A1QSHIP]

I now have a two-car fleet of 1990 20v coupes. Both are red because red cars are faster. The first car turned into a long term project after I clouted an immoveable object. . Anyway, I flew down to Atlanta to pick the car up and drove back w/o any problems. Today, the car acted as if it did not want to respond to throttle application, as if the cable had been disconnected. Previous owner said before I purchased it that there may be issues with knock sensors. Does anyone here have any BTDTs regarding what a defective sensor will act like?
Thanks, Chris

[Greg_S]

I changed mine a while back upon recommendation from Mihnea but im not sure how you could test them im afraid