Jump to content

2013 silverado hellaproblems

austin jez
 Share

Recommended Posts

austin jez Enthusiast

austin jez

Posted
Posted

Hello all. I have a 2013 silverado w/5.3l flex vin 7. Basically has rough idle in park and drive. Very poor acceleration. Almost seems to bog down when trying to accelerate. It will occasionally surge and for just a split second I can feel a bit of power.  Also doesn't want to downshift when I lean on the gas pretty heavy. I've got to do near floor it to get it to down ****** and when it does it will drop down 2 gears a lot of the time. No engine light and it won't set any codes. Showed 0 misfires on all cylinders. Long Fuel trims usually in single digits negs. Fuel pressure 43-46psi at idle and highway. I've replaced throttle position sensor, Accelerator pedal position sensor, manifold pressure sensor, mass air sensor, plugs, coolant temp sensor, oxygen sensors. Fuel pump, intake manifold gaskets twice (now with "updated" steel gaskets), throttle body gasket/seal, injector o-rings (upper and lower). Tested all coils for strong spark. Smoke tested for vac leaks along with propane. It has never failed to start or even had a long start and has never died/stalled. I'm just kinda at a loss at this point. Any help will be appreciated and possibly considered. Thanks

mjm-1957 Enthusiast

mjm-1957

Posted
Posted

See if the exhaust is restricted. You can run it with the front O2 sensors out to check that.

austin jez Enthusiast

austin jez

Posted
  • Author
Posted

Supposedly my fuel pressure is normal with the flex fuel. The ECM regulates the fuel pressure depending on the alcohol content percentage. Enclosed loop it has almost 70 PSI and drops down to about 45 in closed loop. And there's no exhaust restriction. it has no cats. The downstream O2 sensor readings mirror the upstream

austin jez Enthusiast

austin jez

Posted
  • Author
Posted

What's more frustrating than actually having to deal with it running like crap is just knowing that it's probably something ridiculously simple that I've overlooked over and over

austin jez Enthusiast

austin jez

Posted
  • Author
Posted

Fuel sys 1 CLOSED LOOP

Fuel sys 2 CLOSED LOOP

Calc load 16.3 (%)

ECT 196 (°F)

STFT B1 -2.3 (%)

LTFT B1 4.7 (%)

STFT B2 0.0 (%)

LTFT B2 -2.3 (%)

FUEL PRES 44 (PSI)

MAP 9 (inHg) / (kPa)

Eng RPM 602

VEH SPEED 0 (MPH)

SPART ADV. 18 (°)

IAT 84 (°F)

MAF 0.69 (lb/min) / (g/s)

Abs TPS 15.3 (%)

O2 B1 S1 0.748 (v)

STFT B1 S1 2.3 (%)

O2 B1 S2 0.659 (v)

O2 B2 S1 0.820 (v)

STFT B2 S1 0.0 (%)

O2 B2 S2 0.255 (v)

Command EVAP 20.4 (%)

Fuel level 87.7 (%)

EVAP VP -0.2 (InH20)

BARO 30 (inHg)

CAT TEMP B1 943 (°F)

CAT TEMP B2 943 (°F)

ECU volts 14.3 (v)

EQ Ratio 0.999 (%)

Relative TPS 1.6 (%)

Ambient 66 (°F)

TPS B 14.9 (%)

ACC Pedal D 21.2 (%)

ACC Pedal E 11.0 (%)

Command TAC 2.4 (%)

FUEL TYPE NONE

ALCH PCT 3.8 (%)

 

 

shakenfake Senior Enthusiast

shakenfake

Posted
Posted

Well at least it is going into closed loop that is good. When it is in open loop does it run better? 

austin jez Enthusiast

austin jez

Posted
  • Author
Posted

It does seem to run a little better before going into closed loop. 

 

Also, I feel like it goes into OL-Drive "open loop drive"/fuel enrichment prematurely. I'm not certain when it's supposed to kick in but it will sometimes with less than half throttle. The engine load increases very quickly with light throttle. Esp in those times where it just kinda lugs or bogs instead of downshifting and taking off when I'm trying to accelerate at a higher speed. 

 

Another odd thing about a month ago was that my calculated alcohol content percentage gradually increased every time I got fuel until it got to 78%. and it leveled off and stayed until I reset it a few weeks ago. But during that time, it ran a lot better when it was running so rich and fuel trims were maxed out in the negs. Had much more power then but millage was terrible. 

shakenfake Senior Enthusiast

shakenfake

Posted
Posted

open loop normally comes on after a few minutes of drive time or some certain conditions are not being met. 

 

Have you pressure tested your injectors with the scan tool? 

I still feel like the fuel pressure is low. Have you checked vacuum hoses?

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

  • Latest Articles

  • Posts

    • asilverblazer
      Wow I'm in a pickle. (Broke down truck) and a story.

      By asilverblazer · Posted

      There's a bunch of tea leaves that you've read, but in any case the delayed timing is unusual. Not sure how that relates to the rich at idle vs. 'normal' while driving.   If you're in this deep, might be worth investigating, and re-learning the sensor. What have you got to lose? Plus, it properly fixes the timing cover leak.
    • asilverblazer
      Wow I'm in a pickle. (Broke down truck) and a story.

      By asilverblazer · Posted

      The only problem I have seen this cause is longer crank times. 
    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      Injector is being sent off today for rebuild and I estimate I'll have it back in 10 days or so.   It may not be the injector...of course...now that I've torn down the intake again. But, let's rule out the injector and replace those spider legs that have been almost rubbed through.   The truck has always had negative timing and I'm reading "normal" timing at warm idle should be +16 or so. I'm negative 16 to 25 or more, and it's always been like that since I bought it.   A light turned on upstairs last night in the old noggin. Rare, I know...   This will be wild, if it turns out to be the cause!   In 2001, according to the old service documentation, the muffler was replaced. Why? I have no idea, it wouldn't have been rusted through by then. But they did a crappy job.   In 2019, another shop replaced it and noted the prior install was poorly done on the work order. "Exhaust system vibrates on crossmember". Except...I guess they just left it be? I believe the husband, the couple who were original owners, had passed by then. Maybe she said it's just not worth it to have the exhaust system fixed and declined repairs. Very few miles were driven between 2019 and 2025.   The exhaust system vibrates heavily on the crossmember and you can feel it and REALLY hear it, even today. Not always, but at idle, it gets going pretty good sometimes.   What if....   ....What if that's enough to trigger one or both of the knock sensors? Could it be tricking the sensors into sensing knock, so it's pulling timing aggressively? Pulling timing heavily means it's firing after the piston reaches full height which means incomplete burn which means the O2 sensor is sensing a rich condition, which means I've been chasing my tail, and what I thought was an inconsequential problem (janky exhaust) has been THE issue for this truck for 25 solid years?   That would be wild. Maybe it IS wild.   The service documentation thereafter, for years, shows visits for rough idle, replacing O2's, replacing the cat, replacing plugs and wires, a misfire condition, like they could never solve the issue. The injector has been replaced 4 times in 80k miles, that's just crazy.   The secondary theory....   The engine has clearly had a leak at the front seal for a very long time (the greasy trench...). I think the truck changed hands quickly ~2025 because there's Napa receipts from someone I don't recognize in the ownership history. They apparently replaced the timing cover seal, and they did a terrible job. There's RTV smeared all over and the leak I had reduced to a weep by snugging the front oil pan bolts is now a leak again.   HOWEVER....I read about replacing the crankshaft position sensor. Any time the ckp sensor is disturbed or timing cover is removed, the truck requires relearning, and that can only be done through a bi-directional scan tool. Skippy with the RTV probably didn't do the relearn procedure is my guess. His scan tool is lost in a pile of RTV goo somewhere.   So, it's very possible the sensor has been disturbed and the truck is just running on the old learn data but not setting a code for anything. The distributor has since been replaced and so has the camshaft position sensor, so all bets are off for that thing.   In the theme of one step forward, two steps back, I returned the accumulator for the AC. The gal I've been working with at O'Really's has been great. She refunded it under manufacturer's defect and we compared it to the replacement I ordered, and sure enough, the replacement is machined very differently (and a gauge actually fits on it!).   Got it home, installed it, started vacuuming it down.... and I couldn't get good vacuum.   The high side service port, where I replaced the old GM ball valve suspecting that was a source of the previous leak....well, I've clearly exposed whatever pre-existing crack in the line where the service port is welded, and made it much worse. Blessing in disguise? Except there goes another $25, now I'm waiting for a replacement AC line.   In 10-ish days ALL the parts will be here. Rebuilt injector, new exhaust system, new cat, new high pressure AC line.   Oh, did I mention the squeaking ISN'T coming from the AC pump? The truck still squeaks when started, and there were words after I started it with the new AC pump installed. But, there was more to replacing the AC pump for just a squeak. A truck with good working AC is something of value, for the comfort alone.   I've ordered a new harmonic balancer because, 30 years is a good run for one of those. Rule it out. The squeak may be something more sinister, though. I'm worried about that ckp sensor and if it was shimmed correctly, or if the timing set was installed correctly. The squeak may be coming from UNDER the timing cover.   At this point, once I get it put back together, I'm thinking I'll take a 50 mile victory lap and then promptly put it up for sale. This truck is cursed. Betty, from beyond the grave, doesn't want anyone messing with her Blazer. Or maybe she's getting revenge for 30 years of shop visits with that thing.
    • KARNUT
      Gas Prices

      By KARNUT · Posted

      3.59 Kroger’s in Montgomery Tx. 20 cents higher than most around here. Very unusual. Saturday they were 3.49. 
    • KARNUT
      Travel Trailer 2024 2500 HD 6.6 Gas Engine ?

      By KARNUT · Posted

      Starting at 17 running parts for my father’s construction business to haul our equipment. Eventually doing shows, sales and training after purchase. I drove a minimum of 50K miles a year. Half hauling something. After retiring 30K miles a year to the last 2 years 15K miles a year. 2/3rds highway driving. The major contribution to fatigue for me is from anticipation and awareness. I just don’t relax. Too many idiots on the road. There’s two kinds. The group that never leave the left lane tied together afraid to let anyone in doing 80. They’re mostly on weekends. Then the left lane sleepers usually next to a tractor trailer not advancing. Eventually the tractor trailer will drift over the sleeper will wake up. The train moves and the tailgaters who are usually mad as hell. You definitely don’t want to mix with them. The tail wagging bumper puller’s with under powered trucks are holding the tractor trailer up. That bunch are dangerous. I usually pace ahead all that. Unless there’s a gap when I can chill and let the speeders pass. I tried all different types of driving. I stay to the right except to pass, it’s the law that’s getting in forced more now because of road rage. I was so happy when my wife didn’t want to do the camping life. I had enough of pulling for work. The family has a bus and fifth wheel. I haven’t driven either one since retiring. No thanks. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...