Backfiring after head swap...........

[mbsprinks281]

Cant even get it started. The timing has to be off, right?

 

[jaymac]

sounds like the problem.
Have you checked it?
You have fuel pressure?
It won't start, but it will backfire trying?
Have you checked/adjusted the timing w/ a light?

 

[mustangramair]

I just had the same exact problem. Mine was out of time, got it timed and it still acted this way. Then i talked to trick flow and i had the wrong rocker arms, made it run better but still not well. Came to find out a vaccum fitting on the underside of the explorer intake was hitting my valve covers so i had a 1/4 of an inch gap between the upper and lower intake and now it runs great. But yeah i would check your timing and see if it is correct.

 

[mbsprinks281]

Have fuel pressure, have spark. When I try and turn it over it backfire through the intake, and wont start. I guess Ill have to crank her manually back to top dead center and drop the dizzy back in again.....

 

[04sleeper]

Have fuel pressure, have spark. When I try and turn it over it backfire through the intake, and wont start. I guess Ill have to crank her manually back to top dead center and drop the dizzy back in again.....

Thats what I would try first.

 

[Scorcher2005]

have the right firing order?

 

[5spd GT]

Yep, check your firing order to make sure it is correct. If that is correct try spinning your distributor clockwise a little bit at a time to see if it will hold idle.

mustangramair- I had a similar occurance for mine except I tightened just enough to break an ear off my upper intake because the pcv two way valve was sitting on top of the valve cover when I went to tighten it down...unneeded stress to say the least