Originally Posted by dnystrom
He has a CAT 350.
And there is NO "AUTO SHUT DOWN" programmed into these CAT engines on motorhomes.
To the OP, this issue is difficult to analyze accurately without being there. When I had my "no start" condition after changing my one and ONLY fuel filter, I realized that ALL my fuel had drained back into the tank. And because I was stupid enough to follow the CAT instructions in one of the books that came with my motorhome that stated to NOT PRE-FILL THE FILTER, that contributed to my no-start condition.
So, long story short, I had my wife use our home air compressor we put a blow down tip on the air line right at the fuel inlet and sealed the area tightly with rags. I then had her pull the trigger on the nozzle and I waited at the fuel filter inlet for fuel. Yep, here it came. I had already filled the filter. I then installed the full filter. But, still, a no-start condition existed.
So, I removed the fuel entry line that's at the base of the HEUI pump. I had her pressurize the tank again. I waited and, there it came, fuel. I quickly installed that line at the base of that HEUI pump. I then cranked that engine for about 5-6 seconds and, it began to fire off. After about another 5 seconds of cranking, it was purring like a big CAT should.
Well, I never, ever wanted to encounter that situation again. So, I installed shut off valves on each side of the fuel filter housing. Now, I can take my time in changing that filter with ZERO issues of starting or running.
So, while I'm not CAT engine specialist, to have your engine start, run for a short time, and shut down, repeatedly, is a tough one to answer. As has been suggested, it's possible you MAY have some air in the lines and the engine is having a tough time processing that air, 'till it's a solid stream of fuel from the tank to the injectors.
In all the time I've owned this CAT, I've never, ever read where "High idle" is required or even suggested. I've "heard" that it's better for a CAT to high idle when prepping to get underway. Again, never seen it in writing. So, to cure your problem, I'd do maybe one of two things. First, I'd try what's been suggested and that is, once you fire that beast up, immediately take it for a drive. That allows for more fuel to be processed and, potentially alleviating the "possible" air in the lines.
Second, if you're not up for driving it, once it's started, immediately go to a high idle. And, if it continues to do it's timed shut down, I'd continue to do that procedure a few times, to see if things clear up. Let us know what you find out.