thanks for the quick reply gents !
@ glum : i must say this might be a good idea to look closer for a gauge problem but was not performed so i don,t know.
@plovett : the egt gauge does nothing - i looked at it carefully during this. but the fluctuations are pretty quick - the fuel flow really jumps up to even redline and returns very quick, so not sure if the egt gauge would show up such quick changings.
nevertheless- i also believe its either a sensor , wiring or gauge problem because the engine does not show any roughness etc when this happens. i forgot to say the fuel flow always jumps to higher than normal- never saw an abnormal low flow indication.
we do with the 404 photosurvey and laserscanning missions and go depending on the mission up to FL230-250 . but first time i noticed it was a laserscanning at low altitude - 6000 feet.
both engines are brand new ( 80 hours) , delivered by ramaircraft , so i quess it has the improved mechanical fuel pump after seal failures were reported on a 404.
its also equipped with the improved two stage electrical auxiliary pumps as well new unfeathering accumulators , the manual on the c404 calls for aux pumps in low for take off, landing and vapor clearance and high for mechanical fuel pump failure.
when its only the wiring i do not care , my worry is about a slowly dying fuel pump which may suddenly flood and stall the engine- an engine failure with a heavy loaded C404 is everything else than fun.
cheers