I'm extatic! For far too long now, I have been plauged with multiple driveability issues: Hard starting (used to take like 10 cranks before engine would fire), Immediate Fuel Pressure Leak Down after engine turned off, Surging idle until engine up to operating temp (thought it was a CTS problem), Idle Surging when hot in drive (like at a stop sign/light), SES code 44 Lean continuosly, and basically just an overall feeling that the car lacked power.
I started out by installing a Fuel Pressure Gauge, and got a reading of 9psi. The fuel pressure dropped to 7-8psi as I increased the engine rpms.
I then made my Fuel Pressure Regulator Adjustable, and set it to max (cranked all the way down), and got no change in the FP. Thinking I must have made a mistake, I went all the way open with it...still only 9psi. Cranked it back to max.
Replaced fuel pump. FP reads 13psi, and stays no matter what rpm. Engine starts in appxly 3-4 cranks now. No more surging idle when hot or cold. Code 44 has not returned (3 days later). Car is running stronger then ever, pullin like a mo'fo'.
I still seem to have the leak down issue, but i'm not as concerned as long as the pump primes, and then the engine fires right up. I will try a check valve in the line to see if pressure holds that way.

 

what type of pump did you replace the stocker with?

 

i have the same basic probs as you , but my car just seems to die out and lose charge , we think its the starter i already sanke in almost 500 bucks replacing what i thouhgt could be it , no dice were going for starter next the fuel pump , then a rebuild unless i can get my friends crate engine off him that he refuses to sell caise he thinks he will have the time to do something with it (its a zz4 been sitting for almost a year or two now and i offered him 2 grand for it and my pc .lol but he turned it down)

 

wow look at this:
ACDelco Truck TBI Pump

Here's someone else selling this GM Pump
GM-partsman.com