New acert cat starting problem.

Sounds like your fuel is draining back into the tanks and you pumping air. I would be careful with the ether, those new cats don't like it much. I had a similar problem with a primary fuel filter leaking air around one of the seals, I just crancked the top down another half turn, and used the manual priming pump lever on the side of the motor. Started right up, never had another problem with it.

 

Or it may just be that when you turn the key off and go find the can of ether the computer has time to reset and would restart anyway, the next time you find the can of ether in your hand try only threatening the cat with it

 

I've seen air getting sucked in from the hand pump and the check valve on the return side being plugged. Most likely the dealership went thru the easy checks, like lines and filters not being tight. You may want to try a new hand pump, or tell the stealership to put a test one on there to check it. I had a truck come in the other day for fuel tanks not equalizing and I traced it back to the #### hand pump.

 

Cat recently identifyed the root cause of this issue as"Air in the system "caused by the Primary fuel filter base letting air get between the filter base and the filter. The production fix will be a new base with a longer taller nipple. The new base part number is 280-2698. You can also just add a 6V3683 o-ring over the current filter base stud and it should contain your issue.
As others have noted, it could also be a faulty check valve in your hand priming pump.

 

I have a detroit engine that is the same... most days it starts, some days it wont. I am pretty sure there is a pinhole leaking air into one of the fuel lines, draining the fuel back when it sits overnight at the right temperature.
No one will believe me when I say this... just yesterday the mechanic (who had to start it using ether) asked me point blank where the HOLE is. Well, if I knew that I wouldnt be battling to start it would I?

Personally I believe that if I was a guy, maybe the mechanic and the dispatch office would take my comment about air leaking into the system more seriously.

The bright side is I get paid by the hour, so if their equipment is not working, I get paid regardless!