Jump to content

Engine Surge

PrairieGM

Recommended Posts

PrairieGM Enthusiast

PrairieGM

Posted
Posted

1999 5.3L V8

I've been battling a idle engine surge through the winter. It'll surge a couple hundred RPM, between 500 to 900. Runs rough, but usually doesn't stall, it only stalled on me once in a parking lot. If I hold the pedal to maintain an idle it'll run smooth. Only occurs in the winter, eg. 10F or colder, usually on startup but can occur afterwards. Once it warms up it smooth out and the surge goes away. Tough to determine because it's intermittent, even on similar days in the winter it may or may not occur. Never have had the problem occur in the summer. 

Replaced MAF, fuel filter, air filter, PCV. Checked the air intake, have not detected vacuum leaks (not smoke tested though). Codes P0171/P0174, I scanned it and pulled up the freeze frame data from the latest code setting, which if I remember set a couple of weeks ago: 

 

LOAD: 3.5%

Coolant Temp: 63C 

Short Term Fuel Trim Bank 1: 35.2%

Long Term Fuel Trim Bank 1: 24.2%

Short Term Bank 2: 32.8%

Long Term Bank 2: 24.2%

Intake Manifold Absolute Pressure: 34.0kPa

RPM: 908

Vehicle Speed: 20km/h

Air Flow Rate from MAF: 9.39g/s

Throttle Position: 5.9%

 

Not sure what it could be, Idle Air Sensor or intake gaskets? Any help would be appreciated, thanks!

PrairieGM Enthusiast

PrairieGM

Posted
  • Author
Posted

Is there a way to check the regulator? I've checked the fuel pressure before, it checked between 55-62 PSI on the gauge. All in all, it's a good suggestion, it wouldn't hurt to replace it since the truck has 192000 some miles and that hasn't ever been switched. Any other ideas? 

PrairieGM Enthusiast

PrairieGM

Posted
  • Author
Posted

Mike, that's a good idea I'll check those, thanks

 

sdeeter, no I have not. That would be a good idea, l should of done that when I was checking the air intake tube. It's been a little tough, as I've been up at college with no place to work on it except the parking lot. Thanks for the advice. 

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • cherryred21duramax
      Tonneau cover that does not leak water

      By cherryred21duramax · Posted

      Thank you.  I really appreciate the well wishes.  I'm an engineer in the telecom industry, I know hardly anything about marketing.  Over the years I did some videos for nonprofits and web sites for small businesses and the seed was planted.  Agree with over-buying, I started shooting on an iPhone before I got my first DSLR and tripod.   I'm looking at trucks with potentially 150,000+ miles to keep the cost of entry low while focusing on the client experience and equipment.  Good wireless mics for interviews, the right lenses & lighting to look professional.  But I don't want to be late or break down, the stress of emptying a trailer & securing a rental truck right before a gig would negate any savings from buying a junker.  So anything that leaks water, has extensive rust, or generally unreliable I'd like to avoid.   Does GM/Chevy overbuild these trucks for upfitting?  I talked to a local upfitter, they sometimes tie lights & other 12V into existing circuits, which I always thought was bad.  Which is why I enjoyed the AUX upfit switches on previous trucks (odd they mostly come with off-road or work truck packages).
    • silveradosid
      injector cleaner 2021 2.7 1500 silverado

      By silveradosid · Posted

      i guess it might be depending on the type of driving. my 2.7 has 120k miles, changed the plugs at 70k and it runs as good as new. i have not used any injector cleaner
    • Atlas
      Looking at ordering a '26 WT because I want a std cab, std bed

      By Atlas · Posted

      GM's are stainless and have a fairly robust powder coating, although, still not worth $850 in my opinion. They will hold up a lot better than their cheaper steel aftermarket counterparts.   What I like about the GM step bars is dealers will often equip their dealer stock with them. Lots of margin. Which means a lot of people end up buying them because they're already on the truck, even if they don't like them. So it's pretty easy to find brand new takeoffs with hardware on Marketplace and Craigslist for about $250.   That's what I did for my crew cab. I wanted ZR2 rock rails for the look, but with the ability to bolt up GM's assist step package. From GM it's about a $2500 accessory all in. The old folks in my life can't get in the truck without steps. I found the whole package on marketplace for $180.
    • kr477
      Forward collision and lane keep assist still a problem on 2022 refresh?

      By kr477 · Posted

      I am really glad I found this post and this site... We have a 2022 1500 refresh LTZ that has these problems: - forward collision avoidance warning light - lane keep assist unavailable - adaptive cruise control unavailable   The truck was bought as a new leftover in 2023, so it was still under the 3/36 B to B when it went in for these problems earlier this year. It has been at the dealer on and off now for about 110 days now. These are some of the things they have done that I can read on the service tickets. - replace/add ground straps (4) - check all battery cables and vlts - replace serial data gateway module - replace front view camera - numerous reprogramming - a few calibrations (apparently ending with 'learned') Last week when I had it back the truck had those 3 warnings every time we used it except for 3 times. On three separate occasions the truck started and ran perfectly with no (zero) warning messages or warning lights lit - everything worked perfectly. Over that same time period the truck did not work on every other 'key' cycle which I would estimate at 60+ cycles. On those estimated 57 cycles it had the same 3 problems each and every time.   It is back at the dealer now - can anyone help at all with what the true problem might be?  Or possibly what can be ruled out leaving a lower number of possibilities? Thank you very much for any help you may be able to supply....     
    • Z45
      Looking at ordering a '26 WT because I want a std cab, std bed

      By Z45 · Posted

      As for the step bars, friend did just that, bought some cheap ones and we are in Michigan and they turned to rust in less than a year.  In 3 yrs he had to replace one of them because they rusted out from the inside even though he kept after them cleaning and polishing etc. Had to drive 300 miles (to Chicago area) to find a reg cab wt, he ordered one and dealer never got it and with winter approaching (plow truck) he needed fo find one ASAP.  Furd dealer found him one but he choose to drive to get a GMC.    Just what you can expect with cheap stuff, LOW quality. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...