HK07 wrote:

Good point OJ

It cranks for sometime with no fiiring, does that twice and then on the 3rd go it fires a bit then starts and runs nicely and restarts with ease .

No white smoke at all, bit of black when it finally gets going.

Long story but timming belt was replaced short time before the rebuild started, so apart from a good clean, the engine was left well alone. Before reinstallation it had been left idle for 13 months, it fired straight into life with no bleeding or any tinkering, we just connected it all back up and bang it started. But that was in the summer.

Thanks for all your input fellas.

HK07

Certainly sounds like air, have you noticed any recent fuel leaks, start by a check of all the fuel lines right back to the tank, lift pump, fuel filter, and as suggested the injector leak off pipes, when was the fuel filter last changed? Fuel pump?
if it was starting ok before it’s more likely something that’s happened since / when the engine was refitted,
Logically do one thing at a time and try it so you can keep track of what your finding,
Good luck