Have a 93 pontiac sunbird w/ 3.1. One day I went to start the car the only thing it would do is turn over. The block was cracked so I put another engine in. It's doing the same thing. I replaced the fuel filter, it has good preasure in the fuel rail. Has current to the injecters & I had the coils checked & are good. put another brain in also.What would cause it not to fire? This is my first computerized car. Thanks for helping, Steve

have you checked the map,coolant,throttle position and crank sensors. any one orcombo of, can give you the problems you might be having. also coils may be good, but is there spark at the plug?

no spark at plug