Signature 520 CM570 Low power no codes

[4x4Acco]

Thanks! I do have a vacuum gauge i can use for inlet restriction. I will check it at the same time. When it shut down that one time with no apparent reason, the crank angle sensor was my main suspect with it not seeming to play up since, i didnt follow i up. If a crank angle sensor has an intermittent fault, could ti supply incorrect data but the engine keep running as each cam position pulse resets the crank angle count? This was a thought for it running rough too..