HI,

1ST is where has the electrode gone,(piston?)

2ND, The 902p are good for up to approx 2,bar of boost,

3RD, dont have any info of 701c.
I would check out the fuelling, have the injectors flow checked as may be running
weak on n01, have all checked and conditioned, and the engine checked for vacuum leaks, and boost pressure hold test engine. as may be sucking in air and
weak mixture,

DAVE R.