I have recently noticed a cold start issue that I can't find in searches. i have a 13 fit sport 5MT ( 73000 miles) that immediately stalls on cold start up. It's as if I turned the key to start and immediately turn the key off, but even faster than I could do that by hand. It is only on cold starts after engine has been off for a long time. It seems that ignition happens and in a millisecond, ignition is cut off. After trying again it starts up fine and runs smooth with perfect idle. no other issues.

I replaced the gas cap as it always seems too loose and thought it helped as the issue was gone, but I filled the gas tank at the same time which may have been the real cure . The tank is now at 1/4 and the issue has reappeared

I bought this fit with 67000 miles and haven't done any maintenance and I doubt the previous owner did much more than oil changes. air filter is clean

 

That's tricky to diagnose if it's an intermittent issue like that.

Cheapest means I see is buying a Bluetooth OBD2 reader like and downloading a corresponding app like Torque pro.(pretty sure this is Android only though) It'll let you see all sensor inputs and let you log events so you can see what happens leading up to start. It's a far sight cheaper than buying a dedicated reader and is loaded with features designed to capture this exact sort of problem. Depending on what's the problem it also may be an easy fix with a regulator. Even if it's a fuel pump problem the pump access is under the center console, don't have to drop the tank to access the pump.

Lemme know if you want the service manual, I'll pm it.

 

thanks, I do have a hard copy of the service manual and will try to trouble shoot electrical systems as it doesn't seem to be mechanical. I like the bluetooth obd2 reader.
I'll post a solution if i find one.