Recent starting issues. Fuel problem?

Originally Posted by phunk

If you have a return fuel system on your turbo car, usually fuel pressure will not hold more than a few seconds after the pump is off. Aftermarket regulators are not designed to hold pressure.

To crank from zero pressure rather then a primed system should only add an extra 2 cranks or so until it starts.

If the car starts hot, but doesnt start cold, (assuming plugs are good and nothing strange is going on) it is most likely an issue in the calibration. Getting a perfect tune that starts quickly in every circumstance can be harder than it sounds with many computer systems. In my Z, I used to have a random problem with hot starts that I never fully worked out in UpRev, but it would cold start E85 1000cc injectors dead middle of winter 0 degrees out like it was factory stock on a summer day. My mustang is tuned by one of the best tuners in the industry for that platform and it has intermittent issues with cold starting where sometimes it doesnt even start on the first cycle.

Its worth chasing it a bit, to make sure nothing is actually wrong physically with the fuel system or plugs etc. But if you get it nailed down to the ECU calibration, it may or may not be easily correctable.