Rb26dett Misfire Above 4000rpm

[grippy]

My RB26DETT runs a D jetro power FC and a 600hp walbro in tank fuel pump, all else is stock. Runs 1bar (14psi) of boost.

When the engine reaches 4000rpm and the throttle is held constant the engine intermittantly misfires and the turbos chug.

If I leave the foot planted and continue to accellerate there is no misfire and same on decel.

The misfire continues at steady throttle at all RPM above 4000.

Any suggestions on what may be causing this?

I was thinking maybe fuel pressure, or spark being blown out, but strange as it only happens when throttle is held steady.

Maybe MAP sensor or crank angle sensor?

For now I'm baffled.

Will advise if I find out.

Rgds,

Grippy.

[R31Nismoid]

Id pull the coils out and check for cracks or splits around then first and go from there

Could be CAS too, but sounds a bit unlike it to me

[grippy]

I was thinking it may be the coil packs but hoping not as I know how expensive splitfires are.

I have a set on my RB20 I can borrow and try, so I'll see how that goes.

I'll let you know.

Thanks for the tip.

Rgds.

[grippy]

I have changed the coil packs for splitfire ones and the problem is still the same!

Any other suggestions on what can be causing this?

It must be a sensor causing this as it only happens when the throttle is steady.

Any suggestions appreciated.

Rgds,

Grippy