Hey guys, first post here. I am a independent repair company, looking for some input on this machine. I have a 328D cat excavator that is intermittently stalling. Scanned with cat ET. No active codes, only a few logged codes for unrelated stuff and all logged codes the last incident was 6 plus hours ago according to the time stamp. Started a few days according to the customer. Machine stalls throws no codes or events. And starts right back up after a key cycle. 1 out 10 times it will be a crank no start but starts after a key cycle or two. The only thing I have seen on cat et is the status bar shows no engine speed when it stalls. Under data when I crank the unit for 1-2 seconds the engine speed shows abnormal signal then shows proper speed and starts. I'm leaning towards a speed sensor issue. I have the double speed sensor under the HEUI pump coming tomorrow. Curious to know your thoughts, thanks. I have attached the serial number in the picture.
Having had 3 of them. Let's go basic. Drain the sediment/ water from the fuel tank. I average have had continual plugging of the drain 90° fitting. Like, plugged at every oil change. 2nd, the separator drain plug should be easy to turn, and, the thumbwheel needs to be flush to the bowl. They "swell" over time and can allow air entry w/o fuel loss if not fully seated up. And,if still using a water bowl, double gasket or no gasket will cause the same thing.
Update. Scanned it this morning and no communication with the engine ecm, bingo! Performed all powers/grounds, ignition and CDL checks. Everything was good. Got an ECM coming for it. Suspecting the ecm was crapping out intermittently yesterday and this is why I had zero codes or events being logged.
Most likely it is not the ECM that is failing, but the ECM wiring harness that is failing. Even when checking the power wires they may show 12 or 24V, but if the connection is weak or the wire is frayed they will not pass the required current to the ECM..