I have a Holley 4 barrel 4160 600 cfm carb on my GMC 302. I worked fine for years, but recently it develpoed a major problem. When I press down on the accelerator peddle and then release it the carb stays open. To my hand, it feels like liquid (gasoline) is preventing the carb from closing. It will close by hand but only at a slow rate -- kind of like a shock absorber. I plan to rebuild the carb but thought someone might know if I need to replace a specific part rather than buy a complete rebuild. Any ideas?

pull your cable or linkage off the carb and check for proper operation

are you saying the throttle blades are staying open? If so one of two things could be going on here . The bushings on the shaft are sticking, Or cable is sticking in the houseing. Try spraying the carb shaft with carb cleaner and the cable with some WD40 and see what that does. And Get back with us.How does the peddle feel when you step on it? Is it hard? Unhook the linkage and Check by hand. one other question How old is this carb and when was its last Rebuild or cleaning?
hope this helps/starting point }[oooooo]