Sierra cold start

[dhamblin]

Hi Folks, my 96 Sierra just started a strange bug and after checking a few things, am scratching my head and hoping someone has an idea. It happens after sitting overnight or several days without being started. It will crank fine, but will not start. Once started, it runs perfectly until it sits overnight or longer. Checks done while cranking in the failing state include, good spark at coil and plugs, approx 60 lbs at the fuel pressure test port, pressure holds good for several minutes at rest,no check engine codes, scan data appears to be ok ( as much as I can tell),new fuel filter, all connectors are clean and reseated including injector connector (SFI system), PCM connectors clean and reseated. When the truck does start, it will begin firing a little at a time, stumbling as it does, and finally after many tries it will start, smooth out, and then run perfectly as far as you want to drive. Any ideas will be appreciated. Thx

additional info-just checked injector conn on fuel meter body-am getting
12 Volt pulse while cranking this morning-am going to swap out PCM with a buddy who has same truck today just to make sure. Its looking more and more like a pressure regulator, but the good 60lb+ pressure and good holding pressure after cranking stops puzzles me. It looks like bad regulators normally show up on warm engines.........??

[horse482]

With every thing that you have said about your problem it sound like a fuel pressure regulator. Fuel pressure regulators will cause hard / no start problems after when cold or after sitting for a period of time. Good Luck.