2004 5.7 350 mag efi mpi ive been working on this in a boat shop. motor came out out of a ski boat.was all rebuilt by engine shop. here is where t gets crazy. the boss ordered a new engine harness and computer so the engine could be used in reg boat.needed the harness for interrupter switch.and other extras.this engine runs fine for a bout a minuet then starts to bog down.does this have the guardian system built in the computer?i am running this engine on a skid outside the shop .I am wondering if the computer is not seeing a signal?this is the engine with that emc555 system tps tmap etc iac crank sensor no pick up in distributor. I don't no much about the guardian sysem exept the ones n outboards.i used meds scan tool says all sensors are working inj good ing good . or am I chaseing my tail thanks for ny help