having engine problems
 

ok well i finally got my car started again but i have a couple of problems
first off is that my engine is idling at around 500 rpms so i adjusted this and it is now idling at 1000... as for the big problem... my engine is studdering and sputtering even when idling and it seems to have lost ALOT of hp since i drove it 2 weeks ago, but i replaced the gasket on the exhaust manifold to exhaust pipe because the other one was totally gone...also when i let off the gas it backfires very easily and when i turn it off it gives a very LOAD backfire a couple of seconds afterwards..i did compression test and spark plug test and everything is fine so i am thinking maybe its a fuel problem with the fuel pump or carb? or maybe even have a problem with my manifold? hell maybe it just needs a good tune up or the carb needs cleaning but ya...any info would be much apretiated