mustangmoses95

I have a 95 GT 5.0. It started shaking violently for no reason. Did tune up, checked mechanics, everything fine. Engine throws no codes, so I went to get diagnostics, and it said PCM not hooked up to diagnostic. Reset the computer by unhooking battery and cnnecting 2 loose terminals...Ran like a beauty.That was until I shut it off. I had to reset almost every new start, but it would run great when I did. Finally replaced the PCM, now it runs like crap again, even worse...and won't reset. Any input from anyone would be great. Has anyone evr heard of this before? PLEASE HELP ME!!! I WANT MY MUSTANG BACK!!!