Tb42 EFI runs likes hairy goat

[PatrolOwner69]

Hello everyone, my tb42 efi idles good but as soon as you rev it up a bit it will start crackling and backfiring through exhaust . Has been retimed multiple times and is set to about 12 degrees BTDC . My tachometer also dances all over the place when revved I have changed CAS,MAF and both plugs going to them. Is there a reason behind this also has new ecu/injectors/fuel pump/plugs/leads/coil
Cheers

[mudnut]

The most common causes:

[PatrolOwner69]

The most common causes:

Those thing have been checked if not replaced. Tachometer sits at 4 grand when revved slightly. engine light also flashes.
Cheers,Bailey

[mudnut]

So you have used vacuum gauge to test the inlet manifold? There is a thread dealing with the readings different conditions cause on a vacuum gauge, but I can't seem to find it.

I think it is an electrical problem anyway. A loose wire or bad connector.

[PatrolOwner69]

So you have used vacuum gauge to test the inlet manifold? There is a thread dealing with the readings different conditions cause on a vacuum gauge, but I can't seem to find it.

I think it is an electrical problem anyway. A loose wire or bad connector.

Thanks for the help.
Problem has been found. I removed the dizzy and pulled it apart and scuffed back the steel disc that slides into CAS it had a little bit of corrosion on it which must have been giving sensor bad reading.put it all back together and runs a treat.