Just built an EJ257.

First start-ups went very well. Oil pressure was good. Had good throttle response. Was very happy and couldn't wait to test drive it.

But next day I wanted to look at it more closely by logging it, and then it started doing strange things

First thoughts were fuel pressure and fuel filter, but fuel pressure is good and after I replace the fuel filter with a new on nothing changed.

Got compression on all cylinderes.

g/s, coolant temp are normal
g/s go higher when stepping on the throttle, so throttle works.

Final fueling base (estimated afr) is quite strange, jumps around, like the rpms do.
Sometimes timing also jumps around a bit.

Also swapped to my old (stock) injectors and flashed an old map.






Hopefully someone has an idea, what it could be either mechanical or electrical.

Thanks in advance