have done a lot to it checked for fuel and has 52 psi.. at crank. and has spark and did compression test and its good too 140 to 160 .. checked injector pulse and its good replaced cam and crank sensors and was at a Nissan dealer and was told the timing chain may be off too. so I did replace the front timing chain assy. too.. they checked it out and said that would be there next step.. so I did it and still no start..