Signature 520 CM570 Low power no codes

[4x4Acco]

Hi All,

Well I have found myself almost at a dead end trying to diagnose a power loss. So I have a Signature 520 CM570 in a Freightliner Argosy. So i have looked at the basics, connected Cummins Insite and have no active codes and one inactive one which was for low voltage some months ago when i had flat batteries. I have performed a log with Insite whilst driving under load and if the standard information i have is correct, can't find anything wrong. At 1500rpm, a screenshot showed the following... Road speed was 63km/h (39mp/h), Boost pressure was 250kpa(36-psi), fuel pressure 283kpa(41-psi), oil pressure was about 300kpa(43 psi), coolant temp, 91c (196f) oil temp was basically the same... Its set at 575hp and feels like 100hp...

I have performed a top set about 30,000km ago, in the last week i have checked the timing actuators and these look like new (pretty sure these have been changed by previous owner at some stage, I still need to check the metering actuators this weekend. I need to perform an injector leak back test at the same time as i am pretty certain at least one injector is bad.

I have had it shut down without warning once on me about 9 months ago with no indication, stared up straight away and was fine... No codes then either. No problem since. I thought the ecm could be bad, have swapped for a good one and basically runs the same. Engine will rev to governed speed (2000) but just won't pull. Under load it feels rugged / rough but sounds ok.

I have cleaned the map / temp sensor and didn't really seem to make any difference. Did order a new one but they sent the wrong part so waiting for another to be sent.

At the end of the day, the engine is not far from new but would like to get it sorted before i commit to a in chassis rebuild in the future.

Sometime it feels more rugged under load than other days but this could also be me over thinking it all...BTW it idles reasonable most days occasionally rough. Sometimes has that cummins intermitant pop pop pop that actuators can cause at idle but of late has been ok.

Anyone got any hints? :)

Thanks!