I have a 95 Regal with a 3800. If it sits for a couple hours or more it doesn't want to start. I've checked the fuel pressure at the regulator and have between 40-45psi with just the key on. I plugged the return line and it went up to 75psi. I left the guage on overnight and had 10psi in the morning. After it sits if I spray a quick shot of carb cleaner in it, it starts right up. After it started the fuel pressure went to 40 psi. I pulled the vaccum line off the regulator and it went up to 48psi. Saw no signs of fuel in vaccum line. Put a vaccum gauge on FPR and it held 5psi for over a hour. No lights and no codes. Not sure what else to try. It seems the fuel pressure is on the low end but one thread said you need 35psi to start. Note, I am in a cold climate highs 35-40 lows -10 or lower. Any ideas would be welcomed.

This sounds like your CTS is not operating correctly. The CTS is simply a thermosistor; as the coolant temp gets higher the resistance drops. The ECM supplies the sensor +5V and measures the voltage drop through the thermosistor to determine coolant temperature. Some resistance vs. temperature values follow:

*F--------Ohms
210----------177
158----------467
104----------1459
68------------3520
32------------9420
-4-------------28680
-40-----------100,700

The sensor is used for open/closed loop operation and is used in the calculation for fuel and ignition. (Operates like a choke on carbureted cars of the past)

I agree with HotZ28 that your problem is not fuel related. All your fuel pressure readings are well within acceptable ranges.

Do you by chance have a CEL on, and if so, have you pulled the codes?

If no CEL, then I would look into the CTS as HotZ28 suggested, or possibly a borderline bad TPS.

It was 5 below last night so I just unplugged the sensor. Car started right up. There was anti freeze leaking on top of it so I did the intake manifold today and replaced the sensor at the same time. Works great! Thanks for the help.