Advance Auto Parts has the 20-ounce Chevron Techron Concentrate Fuel System Cleaner for $7 with free in-store pickup or $9 shipping. Designed for carbureted or fuel-injected spark ignition engines, use every 3,000 miles to keep the fuel system clean.
Used to date the daughter of a master engine builder for a very large Nascar team... and this was the ONLY stuff he would ever put into his own cars... swore by it and wouldn't touch any of the other stuff (even the stuff that was a major sponsor on one of their cars)... so that was enough of an endorsement for me. Granted, its been 6-7 years, and MAYBE technology has something new and better on the market - but until I find a better source than that guy was - this is the stuff I still use.
Use SeaFoam.
Used to date the daughter of a master engine builder for a very large Nascar team... and this was the ONLY stuff he would ever put into his own cars... swore by it and wouldn't touch any of the other stuff (even the stuff that was a major sponsor on one of their cars)... so that was enough of an endorsement for me. Granted, its been 6-7 years, and MAYBE technology has something new and better on the market - but until I find a better source than that guy was - this is the stuff I still use.