Engine Troubles 351W

[89stang351W]

Okay, here's the story:
I dropped my baby off at a friend of a friends house to have the emergency brake and the power locks fixed (niether functioning). 1.5 days later I pick her up and she is back firing like crazy when I move (not idle) and there is a significant loss of power (like she's not getting fuel). I had a similar issue several weeks ago and it was fixed by adjusting the screws on the carb. But this time the issue is like ten times as bad.

I have received many opinions on the root cause: bad gas, fouled plugs, water in gas tank.

I am not sure where to look first. Any suggestions?
:banana:

 

[93sspcoupe]

check your timing also make sure your plug wires are not cross wired

 

[WillyB93]

X2 but also check and make sure no plug wires are arching across each other!!

 

[FISHTAIL]

X2 but also check and make sure no plug wires are arching across each other!!

Arcing shouldn't cause a backfire, just a miss. Checking for crossed wires is a good idea, but the car would be running like crap 100% of the time if this were the case (even at idle).

I agree you need to check your timing, as that would be my prime initial suspect.