Near stall at stop light

royalkangaroo · February 20, 2019

For the second time in maybe a year, while stopped at a stop light my Sierra 1500 RPMs dipped, and sputtered as the truck struggled to stay running. The whole truck shook like it was about to stall. It's a 2015 with 44k miles on it. I've had it since day one with zero issues.

Anyone have any advice? No dash lights came on. My truck normally idles very smoothly, so I'm unsure of this one-off incident. I put a can of Seafoam in the gas tank for good measure.

jaxcam02 · February 20, 2019

I experienced this with my colorado I had before I traded it in. I had to have an EVAP purge solenoid replaced and it fixed the issue. Wondering if its the same thing here.

"Condition I stated: Vehicle intermittently has stalled on me. Last two times it happened at red lights when sitting for 30-45 seconds and started sputtering. I went to accelerate and the vehicle moved about a foot and shut off in traffic.

What they told me: The tech scanned for codes, no ECM codes found. Test drove vehicle and noticed purge solenoid valve extremely loud (clicking) and long term fuel trims at 24% at idle. Found excessive vacuum within fuel system at idle. Close to -1.00 inches. Tested circuit to valve. Circuit OK. Purge valve internally failing causing vacuum leak which causes random stalling. Also found gm bulletin #16-NA-284 stating there is a new software update to correct temporary lean condition after purge valve test. Replaced purge solenoid and noticed clicking noise gone and fuel trims went down to spec. Also updated ECM with latest software as described in bulletine #16-NA-284. Warranty code #S0334 and #FD812".

papageoff · February 20, 2019

I experienced this with my colorado I had before I traded it in. I had to have an EVAP purge solenoid replaced and it fixed the issue. Wondering if its the same thing here.

"Condition I stated: Vehicle intermittently has stalled on me. Last two times it happened at red lights when sitting for 30-45 seconds and started sputtering. I went to accelerate and the vehicle moved about a foot and shut off in traffic.

What they told me: The tech scanned for codes, no ECM codes found. Test drove vehicle and noticed purge solenoid valve extremely loud (clicking) and long term fuel trims at 24% at idle. Found excessive vacuum within fuel system at idle. Close to -1.00 inches. Tested circuit to valve. Circuit OK. Purge valve internally failing causing vacuum leak which causes random stalling. Also found gm bulletin #16-NA-284 stating there is a new software update to correct temporary lean condition after purge valve test. Replaced purge solenoid and noticed clicking noise gone and fuel trims went down to spec. Also updated ECM with latest software as described in bulletine #16-NA-284. Warranty code #S0334 and #FD812".

Mine's been stumbling at idle more and more. I also have a very sooty tailpipe. I was wondering if I have an egr problem. But this makes sense too.

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royalkangaroo · February 20, 2019

3 hours ago, jaxcam02 said:

I experienced this with my colorado I had before I traded it in. I had to have an EVAP purge solenoid replaced and it fixed the issue. Wondering if its the same thing here.

"Condition I stated: Vehicle intermittently has stalled on me. Last two times it happened at red lights when sitting for 30-45 seconds and started sputtering. I went to accelerate and the vehicle moved about a foot and shut off in traffic.

What they told me: The tech scanned for codes, no ECM codes found. Test drove vehicle and noticed purge solenoid valve extremely loud (clicking) and long term fuel trims at 24% at idle. Found excessive vacuum within fuel system at idle. Close to -1.00 inches. Tested circuit to valve. Circuit OK. Purge valve internally failing causing vacuum leak which causes random stalling. Also found gm bulletin #16-NA-284 stating there is a new software update to correct temporary lean condition after purge valve test. Replaced purge solenoid and noticed clicking noise gone and fuel trims went down to spec. Also updated ECM with latest software as described in bulletine #16-NA-284. Warranty code #S0334 and #FD812".

Thanks - I have an oil change coming up, Ill be sure to mention this. That's essentially the exact same issue I'm having - but it's yet to fully stall.

Sierra Dan · February 20, 2019

5 hours ago, royalkangaroo said:

For the second time in maybe a year, while stopped at a stop light my Sierra 1500 RPMs dipped, and sputtered as the truck struggled to stay running. The whole truck shook like it was about to stall. It's a 2015 with 44k miles on it. I've had it since day one with zero issues.

Anyone have any advice? No dash lights came on. My truck normally idles very smoothly, so I'm unsure of this one-off incident. I put a can of Seafoam in the gas tank for good measure.

Is your warranty up? If not take it in for a checkup. Cannot hurt.

1SLOW1500 · February 20, 2019

Seafoam is good but. On di engines it is just cleaning the cylinder and exhaust. I think your issue in build up in intake. But need codes to help. There are soft codes in the computer. Need those printed out to know. A few things come to mind.