My timing chain jumped on my 07 mazda 6i 4cyl. It was odd because I had done the timing chain and components 20k miles prior. It was at 180k when this occurred. Pistons came up and destroyed the exhaust valves on cylinders 1 and 4. So I decided to cut my losses with the engine, and rather than doing a head job, I got a crate engine with 65k miles on it. I did the engine swap, relatively not difficult. No issues throughout the process. Same type of engine went in as the engine I took out of the car. Now when I try to start it, there's no spark. Compression is perfect, fuel injectors are all firing in sequence. The timing sensor is testing fine. Plugs and coil packs are brand new, cam sensor is new, virtually everything but the long block and a/c compressor is new. I'm not sure what is causing the loss of spark. I'm also only getting 3.5v to the coils on the signal wire. Is it a bad ground? The ECU? Possibly a short in the wiring harness?