Signature 520 CM570 Low power no codes

[CM570_404SAR]

Presuming you're in Australia or NZ if you're running a Signature 520 CM570 (or as you probably know it a Gen II Signature) and using metric measurements.

Have you ever replaced the injectors in it? If not, wouldn't hurt to check the part numbers. If its a CPL 8246 (All the Australian delivered Gen II Signatures are) the part number on the injectors should be 4062568. Those injectors also superseed backwards to a different number when you compare them in QuickServe's CPL Comparison Tool for Gen I engines too.

I've also had an injector shop replace the nozzles on a set of 4062568's that came out of a truck with 1,000,000L fuel burn and put the wrong nozzles on (presumably nozzles to suit the 450-500HP injectors). The truck that motor was fitted in would not pull, we pulled a set of injectors out of a motor that was involved in a big accident (snapped the retaining bolt off and punched the injector cam backwards in the head) put them in and it pulled like we expected it to. We sent the reconditioned injectors back to the shop that did them, they re-did them again, came back got put in the truck and it went off happily down the road without incident after that.

Have you checked for boost leaks from turbo to intake?

Cylinder cut out test? Any noticeable differences per cylinder?

Does the electric fuel pump work? I.e. kick in when key is switched on waiting to start? I'm not 100% sure but I'm relatively confident that under load the ECM can switch it on to help the engine maintain fuel pressure.

The typical cold start rough idle of a Signature isn't anything I'd be overly concerned about, I've only ever seen one Signature start up without it.