You know the story. 2000 4.3 Vortec 4WD, Fuel Pressure. I have done everything that is already on this forum. Replaced pump twice in last 2 years. Once for fuel gauge, once for pressure. A/C Delco pump in it now. Has not helped the symptoms. I have pulled the injectors and totally cleaned and replaced the fuel pressure regulator. I checked it with the plenum panel off and no leaks. Did not help the symptoms.
Looks like the problem is in the fuel pump or the lines. I have replaced the fuel filter also. No visible fuel leaks.
When it starts up it takes about 15-30 seconds to build up fuel pressurebefore it will pull off.You can drive itbut you can tell the fuel pressure is low.The performance stinks.
I have read where it could be the pump or a pressure regulator in the gas tank. Possible that a fuel line in the tank is cracked? I am going to pull the tank tomorrow. What do I look for? I am tired of replacing fuel pumps.......
When bleeding the fuel pressure at the valve above the intake prior to pulling the plenum, only a small amount of fuel sprays out, not what I would think 60 psi would look like.

 

Thanks guys. You were right. I went down and checked the fuel pressure and it was within specs. I noticed that the check engine light was on. I pulled the codes. Mass Air Flow sensor. Checked the air cleaner and it looked like it needed replacement. I also picked up a can of MAF cleaner. When I tried to clean it I noticed some debris on one of the wires that would not come off with the cleaner. I went and got a Q tip and sprayed some of the cleaner on there and gently scubbed the wire. WALA.......Runs like new money. Thanks for the help......

 

Nice! Glad you found the information you required! I must have missed this post in my rounds yesterday. Sorry about that. It's amazing how much affect a dirty MAF sensor can have on the entire vehicle isn't it.

 

indeed. i thought my 4L60E was failing last november, but a $3 can of sensor cleaner fixed it.