Good evening
New to the forum and after some advise on an on going problem I have we BMC 1500 - a brief history
Brought a boat as a restoration project with a BMC 1500 and as matter of course sent for overhaul to local engine company, turned out to be in good order, an overhaled injection pump was fitted also as a matter of course, this engine than ran for about 100 hours in 2021 faultless but towards the end of the season it would not start when the engine was hot, if you left in 20 mins to cool down it would start fine, since then the following work has been done on the engine.
compression check all around 400psi when hot or cold
Head removed and inspected [by the company that overhaled the engine] no damage noted
lift pump replaced
injector pump replaced [another overhaled one]
injectors checked for correct opening and spray pattern
new combustor washers fitted
fuel filter replaced and water trap cleaned
NRV on fuel filter injector pump return line check for correct operation
calibrated hole in the banjo bolt on the top of fuel filter checked
Thought it was all fixed until out on the water yesterday and same problem !
Engine is turned by a new battery and starter motor which turns fast enough (in my option)
Temp gauge shows 80 deg which L would say is roughly right, measuring with a infa red gun, cylinder head is around 85 deg, injector pump is about 65deg.
This engine is not fitted with an oil cooler like some I have seen - does it need one?
The thinking is the fuel is too hot and the injector pump can not make the pressure to open the injectors when been turned by the starter motor - possible ?
it has a 75 deg thermostat fitted - if this is removed the engine runs a lot cooler and starts - (not the answer) would like to get to route cause of this issue and would like your options please.
Photo for reference
Thank you Bob