oh and also another thing i found that was really getting to me was my rpm is only idling at 500 i dont think that is right at all any idea how i can get it to idle at the right rpm

 

and i also have a question about my rpm its only idling at 500 any idea why

 

EDIT: you may have already changed them, if so, disregard everything below. i am talking about the plug wires. if you havent, continue reading.

yeah. the wires i am talking about are the plug wires. they go from the distributor cap to the spark plugs. they are just about the easiest thing to change on a blazer. all you have to do is go and buy a set, lay them out so that all the ends are touching on one end. then you will see that you have different lengths. they come with a little tube of dielectric grease. take ONE wire off the cap, follow it down to the spark plug that it connects to and pop it off. take it over to your new set of wires and match it up to one that is the closest in length. then take that little tube of dielectric grease and squeeze a little bit in each rubber boot. re-install the spark plug wire and repeat 5 more times. there will be one that is really short. that ones goes from the cap to the coil.
when you are putting the new plug wires on, you should hear/feel a little "click" when they have make contact. you need to feel/hear that on both ends. if you dont, pull it back off and put it back on. some times it can be really faint so you have pay attention.

it could also be the reason that your engine is idling so low. if your wires arent any good, they are transmitting enough energy to burn all the fuel. i wouldnt be surprised if your engine is idling a little on the rough side being that low.