Random Misfire
Thread Starter
Cruising
Joined: Sep 2017
Posts: 11
Likes: 0
From: Vicksburg Ms
Random Misfire
i have been trying to figure out a random misfire in my 2011 Grand Sport. I have swapped out everything under the hood with parts off mu 2013 Grand Sport with no change in the random misfire which on occurs at a certain throttle position. the peddle and the throttle body have both been changed as has the mass air flow sensor. I've also tried swapping the fuel regulator. I've changed all the spark plugs and wires. the Torque Tube couplings have also been inspected by dealership. I've pulled the rubber inspection covers on the torque tube and there is no rust or rubber dust in either end. I've put a fuel pressure gauge on the fuel system and it holds 61 PSI while running. Snap throttle causes pressure to drop about 10 PSI for the one second it snaps. after shutdown it holds 54 PSI with no drop for as long as the gauge stays on the system. I haven't been into the fuel tank to change the filter or the pump and was really hoping that would not be the problem. I've searched the engine and youtube videos for the PCV valve and can not find it. would anyone have had this type of problem with a C6? if so HELP. PLEASE
Last edited by Owen MC; Jan 16, 2018 at 04:14 PM. Reason: Add info
Thread Starter
Cruising
Joined: Sep 2017
Posts: 11
Likes: 0
From: Vicksburg Ms
And the two codes displayed are P0171 and 0174. Lean bank 1and2. I’ve checked for vacuum leaks and haven’t found any. Somebody’s bound to know where a PCV Valve is located on these cars.
Burning Brakes
Joined: Aug 2014
Posts: 1,239
Likes: 257
From: Tampa FL
I don't think the LS3 has a PCV valve as most know them. My help is only to show where to look. Not this brand ,but I do have catch and recommend there use.
If you'll read this over you will see what I mean. Best get cheap scanner and know what those codes are.
http://www.eliteengineeringusa.com/t...rvette_LS3.pdf
If you'll read this over you will see what I mean. Best get cheap scanner and know what those codes are.
http://www.eliteengineeringusa.com/t...rvette_LS3.pdf
Le Mans Master
Joined: Jan 2008
Posts: 6,457
Likes: 297
From: corpus christi Texas
It is located close to the passenger side valve cover,you will see a hose from the engine connected to the bottom end another hose connected to the top that goes into the intake manifold.Now days it is called a Purge Valve.....Good Luck.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,435
Likes: 3,981
From: Cape Coral, Florida
i have been trying to figure out a random misfire in my 2011 Grand Sport. I have swapped out everything under the hood with parts off mu 2013 Grand Sport with no change in the random misfire which on occurs at a certain throttle position. the peddle and the throttle body have both been changed as has the mass air flow sensor. I've also tried swapping the fuel regulator. I've changed all the spark plugs and wires. the Torque Tube couplings have also been inspected by dealership. I've pulled the rubber inspection covers on the torque tube and there is no rust or rubber dust in either end. I've put a fuel pressure gauge on the fuel system and it holds 61 PSI while running. Snap throttle causes pressure to drop about 10 PSI for the one second it snaps. after shutdown it holds 54 PSI with no drop for as long as the gauge stays on the system. I haven't been into the fuel tank to change the filter or the pump and was really hoping that would not be the problem. I've searched the engine and youtube videos for the PCV valve and can not find it. would anyone have had this type of problem with a C6? if so HELP. PLEASE
I was reading threads with owners who are having lean codes and other driveability issues. Did you ever get your misfire resolved ??...do you have a scanner where you can scan your O2 sensors and fuel trims and other PID's ??...if you really want to improve your diagnostic skills subscribe to these 2 Youtube channels...Paul Danner aka "Scanner Danner" who is the "Jedi Master" of auto diagnostics...I've watched ALL his videos, got his book and I've improved my diagnostic skills 1,000%...I read all these post where when someone sees a lean code they are all ready changing plugs and wires...idiotic !!....Matt aka "Schrodingers Box" is a DIY'er but really sharp...he is a microbiologist by trade and now I consider myself a "2 Percenter" !!
