Factory Five Racing Forum banner

1 - 5 of 5 Posts

·
Senior Member
Joined
·
7,823 Posts
Discussion Starter #1
I am working on a Cobra that seems to be backfiring through the intake on #1 cylinder. It is a brand new GT-40 crate motor. Any ideas what might cause this? Almost everything is new except the injectors. I can here the injectors firing and they are passing fuel. New wires and plugs.
 

·
Registered
Joined
·
3,193 Posts
I had the exact same problem. I replaced both the intake manifold gaskets and the exhaust manifold gaskets. The problem went away after that.

All the research I did on the subject pointed to an exhaust leak at the heads, but I replaced both for safety. I'm not saying this is the fix, but it did it for me.
 

·
Registered
Joined
·
1,002 Posts
Check that you are using the correct firing order. I've been told that roller engines use the H.O. firing order.
 

·
Registered
Joined
·
220 Posts
A lean condition causes a backfire through the intake. Be careful lean is bad and destructive. Fix it fast. Check the small filter on top of that injector, sometimes it may get clogged.
Tom
 
1 - 5 of 5 Posts
Top