When i cruise around 35mph and let off the gas the car will keep running along at that speed unless i tap the gas the rpm's will drop,also sometimes when in neutral i can bring it up to say 1500 rpms and it will hang there for awhile unless i tap the throttle. What causes this?

Sticking throttle linkage or gummy cable . Mine was doing the same thing last year.

A good cleaning with carb cleaner will often cure this. That is all mine took to fix it. http://www.nastyz28.com/ubb/biggrin.gif

IF carb cleaner fails... Check to see if there is any play in the throttle shaft where it goes into the carb. If it starts to wear out-of-round, it may start to hang there. A stiffer return spring is a bandaid and will cause it to wear faster, so avoid that "fix".

If the hole is wearing out-of-round. The carb can be disassembled, the hole drilled oversize and a bushing inserted. That is the correct way to repair this problem.

If you can get this to happen with the car in park and with the air cleaner off, you may be able to see what is causing it to hang by tapping various points on the linkage with your finger. When you tap the right place and right direction, it will free up and drop back to a normal idle.

Good Luck! I hate these sporadic problems like this.