2000 blazer problem when starting cold

I've got a 2000 Blazer 4.3L V6. W engine, 102,000 miles

When I leave the truck alone for over 10 hours, I have to crank the engine for about a minute or two before it fires up. After I get it to fire and run, I have no problems again until I don't start the car for a long period of time. If I spray carb cleaner into the throttle body it fires but then dies when that is used up. A few more cranks 10-15 seconds and it will start. The longer it sits the longer it takes to get it to fire. Fuel pump always primes and battery voltage is 12 when off and 14 when running.

Also, recently i have noticed that when I'm driving around for a bit, when I release the gas pedal the truck doesn't slow down as much as it should. This is intermittent though.

Fuel Filter and Fuel Pump were replaced two months ago.
Just did a tune-up: platinum plugs, air, oil, and tranny filter, replaced cap/rotor.
Replaced pcv valve, cleaned egr and cleaned throttle body. gonna clean IAC and MAF this week.

The only thing I can think of is maybe the fuel pump is seated incorrectly on the gas tank and pressure is dropping after a while. Does that make sense?

Anybody got any suggestions?

Thanks in advance for your help.

Sure sounds like a fuel pressure problem. Start by getting a gauge and check that pressure. Could be a bad pressure regulator?

I think there's a check valve in the tank to keep fuel from running back into the tank when the pump isn't running. I'm not sure if your rig has that damned CPI injection system or not, but they've been known to leak, and GM has sent out a recall on them to convert them over to the new CSFI. I've also heard of fuel pressure regulators leaking on the 4.3's, but that would cause the engine to run very rich on fuel. The next time this problem happens, turn the ignition on for 2 seconds, then off for 10 seconds. repeat this 5-6 times then start it. Did it start easier? If it did, it's a sign of low pump output, or a leak somewhere. First things first, have the pump pressure AND flow tested.