quickfast50

SHE WAS FINE. I WENT TO GET SOME GAS AND GOT THEWRONG GAS BUT WENT AND GOT SUPER LATER AND STILL SHE ALL BAD.THEN 30 MIN LATTER SHE MISSING AND PINGING AT ABOUT 2500 RPMS. LOTS OF MODS. 331 AND SOMEMO SH...... CANT FIGURE IT OUT IM THINKING BURNT VALVE. I HAVE HOLLEY HEADS AND UPPER AND LOWER INTAKE. NEVER HAD PROBLEM LIKE THIS BEFORE. I NEED HELP.

mxrider426

If i were you i would back the timing down and run a full tank ofsuper through it and then fill it back up and reset the timing. Basically you have to flush the fuel system. But after a full tank of super you should be fine.

mjr46

the gas isn't gonna cause the misfire.........pull wires one by one with insulated pliers and locate misfire when you pull a wire where load doesn't change you have located cylinder with misfire..pull plug and look at it and if you believe you ran enough cheap gas through it to possibly cause detonation and cause damage ...do a compression test on prob cylinder

quickfast50

I checked all wires and no obvious change in motor when pulling each wire. All cylinders are firing.

mjr46

there should be an obvious change each time you pull a wire if it's a hard failure misfire..pull the wire far enough away so as it doesn't still arc.....this only will work if it is not an intermitent load sensitive misfire