Cat Engine 3512B Shutoff

hi all

would some one of you guys help me to solve this problem, if you have any idea?

i have problem with caterpillar engine model#3512B electronic injector, it is driving ac generator.the problem is that the engine is shuting down after period of time, some times run for 3 hours and some times for about 5 hours no problem then it shut down, it start and run fine if i restart it. i checked if there is any fault codes with lap top, it shows event codes: E225-3 which mean engine overcrank, E2087-3 which mean air intake shutoff closed, E038-1 which mean low engine coolant temprature warning. the first two codes are shutdown and the third one is just warning as engine water temprature somtimes is low because there is no much load on the generator.

as per the manual says the recent fault happened, the first one will be showing on the laptop, the code E225 happened first and caused the engine to shutoff, then maybe the module close the air flaps and for sure will get the code E2087. what i dont understand is why the engine is shuting down because of overcrank while it was running. overcrank problem will happen only if the module is starting the engine, for sure it will not crank if the engine is running.

when ever we start the engine, we close the air valve which supplying the starter.

sorry for this long story but my questions are:

is there some problem with the module? or the engine shuts down because of another reason then it is trying to restart but because the starter air valve is closed, it will not start and detect overcranking?

many thanks