Perkins 3.1 delayed start

[LeoKa]

My generator is run by an old Perkins 3.1 engine. Recently, it starts with some difficulties. At first it starts and runs, but in about few seconds it halts. Just like when it runs out of fuel. So, I have to crank it again a bit longer, when it catches up and runs fine afterwards.
I did the bleeding at the fuel pump and at the injectors, but did not change the problem. The fuel pump was replaced two years ago and fuel filter two months ago. Oil change was done last year.
Again, it runs fine forever, once I crank it longer for the second time.
Any suggestions? Thanks

[Comodave]

Did this start to happen after the filter change? If so maybe the filter has an air leak. Easy thing to do is change the filter again and be really careful about doing it and see what happens.

[LeoKa]

Originally Posted by Comodave

Did this start to happen after the filter change? If so maybe the filter has an air leak. Easy thing to do is change the filter again and be really careful about doing it and see what happens.

No, it started before the filter change.

I had a leak at the heat exchanger, which resulted in overheating of the coolant, which shut down the engine. After I fixed the leak and filled up the coolant, it started to run again, but I had this problem with the start.
Again, once it starts it runs fine.

[LeoKa]

Here are couple photos. The engine and the ECU.

[TowLou]

Sounds like air in the fuel somewhere. Dripping injector or injector pump? Get a oil sample see if there is fuel in the oil. Even the supply lines maybe a high spot getting a air bubble in there could be bleeding back to the fuel tank, runs for a moment pushing the fuel it has left then falls on its face from air in the supply side.

[LeoKa]

Originally Posted by TowLou

Sounds like air in the fuel somewhere. Dripping injector or injector pump? Get a oil sample see if there is fuel in the oil. Even the supply lines maybe a high spot getting a air bubble in there could be bleeding back to the fuel tank, runs for a moment pushing the fuel it has left then falls on its face from air in the supply side.

Not a bad idea. I will check the supply line, although it has not been disturbed and it is below the pump level.

[TowLou]

Not to much in a diesel that will cause those symptoms. Assuming compression is good since it runs then bogs out and fires back up after a little priming. Timing/Ignition is assumed to be well again fires up for a few then bogs out. Last is fuel assuming good filters and such and good fuel no water in there it can be a bugger to find but maybe a oil analysis can help pinpoint something internally. That be my line of thought air getting in the fuel from air ingress somewhere.