steele901

i resently put gt-40p heads and an e-303 cam in my 95 gt and now at high rpm shifts when racing my car backfires and shoots fireballs out of the right exhaust pipe. it doesn't always do it, i think it only does it if my motor isn't warmed up. one of my buddies seems to think i'm floating valves. does this sounds right or could it have to do with my 94-95 computer that doesn't responde well to engine mods? i plan to get my car sct tuned so hopefully the tune will clear this up. what do ya'll think?

lookinforastang

is it when u let off the gas?

sounds like its running wicked lean

what octane was in it?

steele901

yeah, when i shift. it doesn't do it if i power shift but i dont do that to often. i put premium octane in it. bumped it up from 89 but didn't make a difference with the backfiring. helped a ton with gas milage though

lookinforastang

well the backfiring is excess gas getting burned by the heat in the exhaust

i still say ur running way to lean

try some 87 octane

fordguy17

if there is excess gas in the exhaust you would be running rich...

92hatchLX

I wanna see! get a video of it!

lookinforastang

yea i just mixed em up.

weird he said hes getting better mpg lol

steele901

yeah, i'm definately running rich. one of my buddies was sitting behind me in traffic the other day and said my exhaust about made his eyes water. plus every time i hop out of my car the gas fumes almost make me pass out. hahaha i'm sure a good sct tune will take care it... hopefully

steele901

i said i started getting better gas milage when i went to premium, not when my car started running rich. 40 more miles on a tank on the highway, no joke.

ikeybmg

you should try to adjust your tps sensor. maybe even reset the eec and setyour base idle. clean your maf, iac motor etc.