I replaced my throttle return spring bracket and spring back to stock over a year ago using Mansfield Restoration parts. I have had no issues. I started the car up yesterday and couldn't get the rpm to go under 20,000 through the pedal. I revved it multiple times but it hung up at 20,000. I went into the engine bay and could reduce the rpm by hand manually returning the linkage to the idle position. Gremlins must have gotten into the car because it makes no sense. The throttle return spring is now loose and flopping in the anchor holes. No tension what so ever. No changes were made. What would have shifted to cause the spring to be loose now? I have it working again through the pedal by putting an aftermarket spring on and cutting it to create the tension needed. But of course, that only masks the problem.