Back firing into intake???
 

I have a 92 mustang coupe with a fresh 306ci and it bask fires into the intake when its cold? Any suggestions?

What type of fuel/air management system ?
( Carb or FI )



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FI

If it runs ok when it is hot then
 

Lean mixtures burn longer than rich mixtures. You are likely very lean no matter which type of fuel system you have. What is causing this problem? Several things could cause this but the problem is likely a lean condition. Lean mixtures can still be burning from the previous power stroke and flash off the incoming intake charge when the intake valve first opens to fill the cylinder on the following intake stroke. Rich mixtures run out of oxygen and finish burning in the exhaust often in the form of a backfire when oxygen gets to the unburned fuel. A bad regulator or a too small injector or partially plugged injector, low fuel pressure, etc, etc.
Bruce

My instincts says timing.....
I don't know ...
MOHO