[Jayjayuk]

Hello all,
I'm having issues with my loved z275. I've have a full engine rebuild and it runs and sounds perfect stint ting at the dock, but as soon as I stick it into drive and pull away it starts coughing and farting with backfires from the outlet manifold😟
I've replaced plugs, leads, coil, distributor, injectors and don't know what to do next as I'm baffled!
Really hope someone out there knows what this might be??
Please help😁

[Hudson River Steve]

Sounds like a timing issue. Who rebuilt the engine? Have you verified that when the engine is at top dead center the pointer on the crank reads zero? Have you verified the timing marks on the crank and cam match up? If these are not correct you will never get the ignition timing correct.