I have a 92 gt and just bought a cobra engine, I didn't know it was a cobra till I went to by spark plugs and I compared them to the ones it had and they are off a cobra so that's why I say its a cobra. Any ways, I bought the motor but before I bought it I turned it on wen it was in the other mustang and it turned on nice and strong. I just finished puting it on my car and now it doesn't want to start up. It cranks and cranks but no start. At times it sounds good like it back fires "pop" but no start. I checked the timing and its correct. It has spark. I checked the fuesable link by the brake booster and its good. Does any one have a clue on how to turn it on? What's the "S" on the vacuum tree by the brake booster for? Is it to "START"? I dnt have it connected cuz the hose tore but I dought its the reason for not turning on, but again im not sure. Thanx.