i have a 87 chevy (truck) with a 4.3 v 6 and i only get 200 miles a tank.When i start it up i have to wait about 5 minutes to drive or it will back fire and once it is warm i have to hold the gas pedal down to start it.Can i get any input?

 

Time for a good tune up, wires, plugs, clean injectors, etc., you'll prolly want to take to a shop, because of all the electronics. It should get 20-24 MPG.