The tachy noise did nothing more to start the engine with the new strap?
Pussy then it is injector, but an injector sounds differently to when it is bad point. I explain:
if it goes spot, replace or rattle like when you throw etherd (itchy rod, the diesel enters early).
And if you have a dead injector, a tas tas tas tas are heard very clear ... and the rest of the engine sounds normal.
The tas is the diesel that drips from the nozzle and peta when it comes out of the noses in half compression, which imagine the oyster that hits while the piston is climbing.
The best thing you can do is get the injectors and try them, if it is much better in the bank, anyway it only is seen whether a dripping injector or not.
So I apologize, I have sneaked, it is because of the injector.
All the best.