FIX THE FUEL PRESSURE PROBLEM.

I agree with Mike and carfixer007 above ^^^^^^^

Fuel pressure needs fixed.

I'd still like to see these questions answered:

I have had a certified GM technician saying that I was condemning the fuel pump because the car was running after a while which would mean it was running hot and therefore after running hot the car would not restart. I have experienced fuel pumps failing in three to four different ways. When I put on the Autel, they gave me a fuel bank 1 lean code witch maybe a fuel pressure sensor, or it could be a failing fuel pump. If the car is running for a while and months continuously without shutting it off oh, that'* fine, however in this case when you shut the car off you cannot turn it back on it will not start oh, and tell the car is cooled off enough. When the vehicle is restart it runs just fine and idle. When I replace the EGR in idle air control valve 3 weeks ago it ran perfectly, no hesitations nothing, however now when you go up a hill or try to go on the interstate and accelerate it is sluggish. I am either figuring it is a fuel pressure sensor or a bad fuel pump. I could not imagine a bad fuel pump which is emerged in fuel in the tank going hot, however the quails in the fuel pump could be just going out all together! Anybody have any ideas let me know. Thank you very much!

Ummm . . .

We did, like 3 times, here comes the fourth time... replace the pump. What part of replace the pump do you not understand?

What? This is one of the most bizarre statements from a tech of any kind that I have heard.
Until you fix your fuel pressure problem I'm done here.

^^^^ What he said.

If that statement is accurate from that man the only thing he was certified in is gibberish.

I'd have to agree with the others that this one takes a bit of effort to untangle. Adding parenthesis like a math equation would seem to help:

I have had a certified GM technician saying that (I was condemning the fuel pump because the car was running after a while which would mean it was running hot and therefore after running hot the car would not restart).

Looking at it this way, I'd have to agree with this certified GM technician: I believe you are condemning the fuel pump because the car was running after a while which would mean it was running hot and therefore after running hot the car would not restart.

. . . especially if that'* what you told him/her.

This is a big part of why I have asked the same group of questions three times before this message:

Unfortunately it appears these questions have not been answered as of yet. The nature of using a text-based support forum to assist in troubleshooting requires that the party seeking assistance make some attempt at reading and answering questions from parties supplying assistance. It is also important to acknowledge suggested courses of action and either take it/them, seek followup information, or mention why you are not taking them before returning and asking [anyone for any ideas] again. Several ideas have been given, and best I can tell they have generally been missed or ignored.

Back to my questions, there are reasons for each one of them that perhaps will compel you to answer:

Bad fuel pumps often present by slowly ramping up pressure, however, yours will start at 55 then go down to 28. Perhaps something else is going on? What could that thing be? I'd start with the fuel pressure regulator. Hence this question.

How do you know? This appears to be speculation, therefore may not be happening. If you have actually determined that the fuel pump is operating at 234 degrees Fahrenheit (for example), this would change things. High temperature in electric motors is often related to low voltage, but could be related to other things. Hence this question.

Really, this matters. Is the fuel pump operating at 234 degrees Fahrenheit with a half-gallon of gas in the bottom of the tank? . . . or is it completely immersed in a full tank of fuel? . . . or somewhere in-between? If it is full then the pump should cool off in a few moments when shut off. If empty it might take a while. That'* if it is hot at all. Hence this question.

Are you telling us what is coming from a sensor? . . . or what is coming from an actual gauge connected to the fuel rail? One is more reliable than the other. Hence this question.

Are we talking about a 5,000 mile car? Are we talking about a 400,000 mile car? Or somewhere in between? Any of these answers affect our diagnosis. Hence this question.

Unless this is a low-mile car (that I can't verify until you answer a different question), the wear level of spark plugs often comes into the equation. Why not ask now? Especially if it will take multiple asks to get one answer. Hence this question.

I don't know what you mean by gibberish, when I put on the pressure gage , the fuel pressure is etnyre 55 lb . After that car has been running for a while it gradually goes down to about 37 . However the car continues to run unless you shut it off after it has been running for a while . You have to wait until it is somewhat cool off before restarting . If this is not a fuel pump issue then what causes this issue on a 3.4 l to be sluggish and when you shut it off after it has been running for some time before you are allowed to restart it ? I hooked up the Autel originally and found that the EDR was halfway stuck, also replace the idle air control valve (IAC). I knew for a long time that the (IAC) was a problem because the car would stall every time you would go to a complete stop. I pulled it out twice and clean the carbon from the unit itself in the orfice it fits into. After replacing both parts, the car ran great for 3 days, then it was sluggish and not able to go up hills. When you put a load on the engine basically it is sluggish. Basically you have to wait till the engine is cooled off somewhat before you can take off again, it will not start immediately after turning it off. Something is getting hot and preventing it from restarting. If it'* not a fuel pump overheating, what other thing could cause this?