Jump to content

2000 GMC 5.3 stalling?

RonnieT
 Share

Recommended Posts

RonnieT Enthusiast

RonnieT

Posted
Posted

I have a 2000 GMC 3 door Sierra  Automatic  loaded with 170,000 miles, well maintained with records kept.

  Its been stalling lately and surging  enough to be scary in traffic.

Also when I start it cold of the morning , I stand beside it and reach in to start and it has been idling low to the point of dying at least once, starts ups are good though and I always allow it to come to temp before driving. Past few days I got in the seat and turned on ignition and stepped on the accelerator before starting to give sensors a voltage value, it didn’t help.

  Today I changed the fuel Filter and it needed it but I have seen worse,

I placed my old scan tool on it and took some screen sots of it while idling, the only code was PO171 that said it was Too lean.

I looked for air leaks on the vacuum hoses and purge vale and all along the air intake boots for the MAF sensor to the valve plate , I see no cracks or breaks , nothing.

 Is there anyone that can look at these screen shots of my scanner and give me a  good guess or where to look and how to find my problem?

     Only major repair on engine was done by me about 6 years ago and I changed the Knock sensors because of detonation  and I used OEM sensors and Felpro gaskets,  I was a  Mechanic for about 25 years in the 80s-90s.

  Any help would be appreciated

KIMG2548.JPG

KIMG2549.JPG

KIMG2550.JPG

KIMG2551.JPG

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted

Agree, what is your fuel pressure.  The fuel pumps on the GMT800's was a main failure item.  If the fuel filter was in bad shape it could have put more stress on the fuel pump. 

 

I pulled my bed off to change the pump.  It is easy to do with two people.  Way better than trying to tackle it any other way.

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

With the vacuum regulator it's probably around 50psi at idle and it should change if you pull the vacuum line off. Under load it should always be above 50psi and closer to 55-58psi.

RonnieT Enthusiast

RonnieT

Posted
  • Author
Posted

Ok, didn't think about pulling the vacuum off the regulator but I have  exactly 45lbs on the gauge I trust  at the fuel rail with key on and engine dead, I have exactly 45lbs with engine running and  regulator working.   so this isn't good,  causes for stalling and  surging?

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted
37 minutes ago, RonnieT said:

Ok, didn't think about pulling the vacuum off the regulator but I have  exactly 45lbs on the gauge I trust  at the fuel rail with key on and engine dead, I have exactly 45lbs with engine running and  regulator working.   so this isn't good,  causes for stalling and  surging?

Yes, the fuel pump is going out.  Time to change it.  Like I posted, it is easy, worst part is getting to it and I opted to take the bed off.

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

If you can tape the gauge to the windshield, see what it does with a load on it.

RonnieT Enthusiast

RonnieT

Posted
  • Author
Posted

Ok, what brand is good for new pump? My fuel gauge is always been a POS and I thought if I ever changed the pump I would change the hole unit. I don't have a lift or transmission jack anymore  so I may just tilt the bed.? 

 I see that make about 3 different ones is the code on the build sheet?  Tfc or TFU or? Ron

   

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted

Best thing is to contact the dealer with your vin.    They can tell you what you need.  That is what I did.  MS3dale who isn't on here much works at a dealership and helped me out.  Then once I got the correct part number I got it off Amazon for a good price. 

RonnieT Enthusiast

RonnieT

Posted
  • Author
Posted (edited)

service sticker says  EVA but I can get the  Vin ,OK if someone can look it up? its better than having the wrong pump in hand with the bed up.

    Ron

Edited by RonnieT
RonnieT Enthusiast

RonnieT

Posted
  • Author
Posted

Ok I placed the Pressure gauge on the windshield and drove around town, 30-50 miles an hour, the lowest on the gauge was @45PSI and the highest was about 48PSI fluctuated while moving and steady around 45 while idling. 

When I got home I took the vacuum hose off and plugged it and the gage grew up near 50PSI  never anymore.

 VIN is 2GTEK19TSY1222104  if someone could help with a pump part number, I am thinking to change to whole unit out.

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted
56 minutes ago, RonnieT said:

Ok I placed the Pressure gauge on the windshield and drove around town, 30-50 miles an hour, the lowest on the gauge was @45PSI and the highest was about 48PSI fluctuated while moving and steady around 45 while idling. 

When I got home I took the vacuum hose off and plugged it and the gage grew up near 50PSI  never anymore.

 VIN is 2GTEK19TSY1222104  if someone could help with a pump part number, I am thinking to change to whole unit out.

I contacted MS3dale.  awaiting to hear back. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,947
    Total Members
    8,960
    Most Online
    Sothpaw27
    Newest Member
    Sothpaw27
    Joined

  • Who's Online   2 Members, 0 Anonymous, 420 Guests (See full list)

  • Latest Articles

  • Posts

    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      www.enginelabs.com/news/what-i-learned-today-bearing-clearances-vs-oil-viscosities/     www.enginelabs.com/news/oil-viscosity-can-the-numbers-be-misleading/ The Big Lie… Coming full circle to the reason Lake discusses the Porsche engines in particular. Based on the 2000 samples in the SPEEDiagnostix database, increasing the oil viscosity in these engines, even those run on the track, showed no significant difference in results.   The smoking gun was in the oil chemistry. That is where the data shows higher instances of more wear. Molybdenum was the key; the higher the amount, the less the wear. Speed postulates that higher viscosity oils have more thickeners to artificially inflate their viscosity numbers. These thickeners lose viscosity under shear, and the result is that not all oils of the same viscosity have the same shear stability.   Having enough viscosity is the most important characteristic, but according to Speed, once that required viscosity level is reached, additive chemistry matters more than additional viscosity. Speed also states, oil pressure problems on the racetrack aren’t a viscosity problem; it’s an oiling system problem. Running a thicker oil is just a band-aid for an underlying oiling system problem.
    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      Can it still be Assembled II?   Viscosity on the decline by various means. Heat on the rise making that worse. Engine RPM in the tank. Smaller motors with more boost trying to emulate an electric motor. Full torque, zero rpm. Then we will triple the OCI. Argh.    But wait....there is more. LSPI has pushed a shift from Ca to Mg and as that cost more PLUS the run to lower sulfur compounds the TBN is moving in the wrong direction for the increased OCI's demanded.    That not being enough to placate a demand for a parameter they can't measure the other sulfur bearing compounds are also under attack. That would be zinc and phosphorus sulfonate compounds. To some degree those are being replaced with boron esters and others, i.e. titanium ect. All of which have shorter service lives. And there there is the "Secrete Sauce" marketing for AW adds that 'Can't be detected by UOA's" but trust me because I (the blenders) never ever lie.    Spoiler alert; ALL additives are sacrificial! Smaller amounts of the old blended with less robust versions of the new do not equal longer service lives. So what are the blenders recommending? Wait for it.......   MOVING THE GOAL POSTS! OMG      Let's declare the long standing TAN/TBN crossover irrelevant and tell people that soot is a great 'graphite' based lubricant which can aid tribo films. Wait, what? Let's declare that the standards used for oxidation and nitration were to conservative and can be expanded. Let's tell them that because GDI fuel dilution, although being a VISCOSITY KILLER and an acid generator is actually okay because we have better base oils that limit viscosity failure limits. (Said knowing this is measured in fractions of a centipoise and in bases not commonly used in shelf oils)   Lying from the heart is not just the new normal but we have a public, a very young public, that is so ignorant of the facts and so sure of their "RESEARCH" into AI driven models base in regurgitated  instead of scientific research based unvarnished, peer reviewed FACTS that the incoming guard is loosing their grip on reality and the OEM's are tickled pink while the blends bend the knee.    You have an ever limited set of tools to work with. And sooner or later those will be taken from you as the API and the EPA strangle the last remaining fluids from the system. What you have left is your wits. If you care to use them.    At some point in the very near future it will not longer be possible to do "What is best for the machine", and be replaced with "The best you have access too". You WILL be rewarded with half the life and twice the cost. That isn't that hard to predict.         
    • Chuck FB
      Software Update

      By Chuck FB · Posted

      I trust you saw the other comment where he knew what he was talking about !. Yes, these darned newer vehicles with all their so smart they are stupid technology, goes and drains the battery down. As you might see my other comment, I installed a Noco 5 battery tender under the hood and at this point still have the cord routed so I have to lift the hood and then plug it in but am typically parked in a garage or a shed so its not risking the engine hood in the wind. That way I am assured or hopefully so of not finding I have a battery drawn down and can't even start the truck and that also damages the battery to draw it down too far. 
    • Chuck FB
      Software Update

      By Chuck FB · Posted

      I guess no surprise my guesses were wrong !, at least now I know if I ever happen to see it grayed out in my own truck as to what is going on.    I never happened to catch my truck with it grayed out, it seemed every time I would test to see if there was an update it never found anything and yet more than once I would check to see if there was an update and there was nothing, then a day later or even that same morning I would drive to town and after more than one engine shut down in town as I did my errands it would pop up that there is an update now ready to install and the only place I have a connection to the internet is at home by wifi so its not as if it grabbed the download while driving. I don't trust these new vehicles due to all the crap they can decide to do while sitting for some days not running and run the battery down so most of the time if I know the truck will sit for a few days I plug in the battery tender I have mounted under the hood and so the only time the truck must have downloaded software was when it was sitting in the garage where the signal is awful but I have that tender plugged in and somehow it managed to download it. I honestly detest all this crap, way to easy to leave a person stranded.    Since I don't trust any of it I don't do the install of the already downloaded software until I get home and sometimes have even sat in the truck to watch what its doing as its going through the process to its conclusion as its not like it is set up that it will tell you the next time you fire up the engine that the update that was initialed actually installed or installed properly. Yes I can go into the updates and see the list. After I go through the install where I feel its safe to do so in case it breaks down as a result, I will plug in the battery tender after the fact to recharge as I don't know how much power its taking just to do the install and that can take a while for it to install. 
    • nfisherman
      Software Update

      By nfisherman · Posted

      Thanks for the reply. All settings were correct and the engine was off, as it was supposed to be. It turned out to be something simple. I took a drive for about an hour. I must have had a low battery without knowing it. The voltage gauge on the display looked ok. At the end of my drive, I shut off the engine and the update prompt came up and it updated normally. It’s ironic because one of the features of the update is a reduction of battery drain. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...