99 tahoe with 5.7 won’t stay running!

[exp500]

Swap the relay,see if fuel pressure comes up. When you had tank down last Did you test voltage at pump?

 

[OR VietVet]

I gotta say that the O2 sensor can effect the engine running. I recently had that exact same sensor go bad and before was replaced, I had to keep the engine rpm's up at stops or engine would die.

 

[exp500]

In that case, he needs to use live data and look at fuel trims among a few others. Still haven't narrowed it down far enough to focus on a main issue. How long did it take to get a 2 fuel pumps in 3 years history? Will he even try to voltage test when he swaps relays? I hope so. It really seems like some expect the scanner to repair all faults just by plugging it in.

 

[ANder]

In that case, he needs to use live data and look at fuel trims among a few others. Still haven't narrowed it down far enough to focus on a main issue. How long did it take to get a 2 fuel pumps in 3 years history? Will he even try to voltage test when he swaps relays? I hope so. It really seems like some expect the scanner to repair all faults just by plugging it in.

So the tech had the diag comp hooked up while driving in parking lot and said this: All scan data, including fuel trims, 02 readings, MAF sensor value and MAP reading are all normal.
idk what voltage should be while looking at the relay.
I swapped fuel pump three years ago. Replaced it with the same pump because it was under warranty.

 

[ANder]

I

Swap the relay,see if fuel pressure comes up. When you had tank down last Did you test voltage at pump?

did not test voltage at pump, but the odd thing is it will rev up as high as I want in park or neutral. But when loaded in gear and hitting gas it falls on its face. If I barely touch the throttle it will get up to speed and run fine but the second I lean into it, it wants to die. Idles fine in all gears also

 

[exp500]

You really need to find a mechanic friend that likes free beer.. Swap fuel pump relay should be one next to it you can use for now. Then drive around block.

 

[ANder]

You really need to find a mechanic friend that likes free beer.. Swap fuel pump relay should be one next to it you can use for now. Then drive around block.

Lol yeah they have given their advice already