What could be wrong
Ok guys let's see who can solve this mystery...
Finally got my 91 mustang gt running and on the road, sounded great ran great until ran for over an hour or so, started skipping losing power and making a strange noise from valve cover and loading up with fuel, wouldn't run with fuel pump on.
Got it home took valve covers off and had a couple loose rockers but they were non adjustable talked to a buddy of mine and he said they were the wrong heads and that I needed roller rockers, and gave me a set of Windsor jr heads.
I got them all hooked up new gaskets and adjusted the valves. Only thing other than heads that are different is the upper intake put the one that came on it back on, got it all done fired it up and it runs like a bag of crap like the firing is messed up backfiring, and almost like it's not running on all cylinders????
I have changed the plug wires thinking they were bad and reset the the tdc and distributer definitely not 180 out and still using the same Windsor firing order my fuel pressure is 39psi.
I'm lost right now not sure what to do or what is wrong. Is there any way the intake could cause this? I ask because this is how it ran when I got it but have since rebuilt it and it ran great with the other intake I just don't see what could be wrong with it to cause it
Any info advice or knowledge would be greatly appreciated thanks