Hey their
I happen to have a 2001 suburban 1500 LS v8 5.3 engine just bought it a couple months ago. I was driving one nigth and while on drive it just turn off on me I tried to turn in on and won't start up. Good thing I was near home and pushes it a couple blocks down. Next day I tried starting it rigth up and had no problem. Once on I will hear a clunking noise like trying to stall. A few times it would just stall I notice the clunking was more from the rear muffler and sometimes white smoke will come out and times some watery residue also times black in color . I attached a OBD and will show P0300 multiple misfire

I have change spark plugs and spark plug wires and still no difference after I change fuel filter same or worst. I notice if I try to rev it it would lose power and stall .
I tried to put it in gear and will just plainly stall could any one please help 🙏 has 178,997 miles

 

Need to check fuel pressures. Could be bad fuel pump or bad regulator.

 

Thank you for reply I will be updating you once I change that fuel pump and regulator .

 

You might want to test the pressure regulator before you install a new fuel pump you might not need, RulloA28.

 

Update So I change the pressure regulator (used from pick your part ) and when put in drive was fine for a munite and then stall after that I turn it on a couple times and will just stall...... Second I will need to replace that pump ...