2010 Tahoe/Erratic idle (no codes detected)

[1-oh-Hoe]

I just picked up a '10 with a similar issues. I ran a bottle of SeaChem injector cleaner through my last half tank of gas. The wanting to stall at idle cleared up for me. YMMV but it's a pretty cheap gamble even if it doesn't work.

 

[SNES Avalanche]

OP: https://www.tahoeyukonforum.com/thr...ot-find-the-cause-fuel-pump-injectors.132624/

I've spent 3+ years tracking down this issue and have gone through a bunch of parts.

1. What is your Oil Pressure at warm idle? From the factory they all sat at 40 PSI. (Yours is most likely at 20 at warm).

2. Can you test your catalytic convertors?

In the end I simply bought a Diablo tuner and increased my idle RPMs by 150. Seems to have solved the overall issue and I'm not going to dig further.

 

[H2oboyz]

I have a 2010 Tahoe LT with 179xxxx miles that I purchased 3 month ago. My idle is erratic and sometimes stalls when I'm at a stop. It drives fine when I'm on the gas peddle driving it's just when I'm at a stop it goes crazy and sometimes stalls out. I will even put it in neutral while driving it and you can see the idle going crazy and sometime stalls out. I have no engine check light on! I hooked it up to an OBD 2 reader anyways and nothing but when I ran a scan on the engine there are all kinds of codes that pop up from HVAC, o2 sensors, and a few others I can't remember off hand. I'm not very experienced with the scanner but why is the OBD reader not reading anything but the scanner is reading all kinds of codes. I'm using a Foxwell nt501 scanner made for GM trucks

What I have done so far:
- changed out the spark plugs and wires.
- changed out the body throttle and (relearned it to the ECM with a scanner)
- checked the vacuum system by pushing smoke through the system with a smoke machine and I sprayed carb cleaner around the hoses and found nothing.
- changed out the exhaust manifold gasket only because I had to replace the oil pressure sensor
- I reset the Alcohol fuel content because it was showing %17

I'm thinking of replacing the VVT next. I want to change out the water pump anyways just because I don't know if it was ever changed out.

Try resetting the throttle position sensor. It sounds cheesy but it worked for me a couple times when I was having similar problems. I’m in a 2012 Chevy Tahoe so we’re pretty close to the same vehicle. Good luck. Let me know if it worked for you and have a great Christmas !!

 

[H2oboyz]

I have a 2010 Tahoe LT with 179xxxx miles that I purchased 3 month ago. My idle is erratic and sometimes stalls when I'm at a stop. It drives fine when I'm on the gas peddle driving it's just when I'm at a stop it goes crazy and sometimes stalls out. I will even put it in neutral while driving it and you can see the idle going crazy and sometime stalls out. I have no engine check light on! I hooked it up to an OBD 2 reader anyways and nothing but when I ran a scan on the engine there are all kinds of codes that pop up from HVAC, o2 sensors, and a few others I can't remember off hand. I'm not very experienced with the scanner but why is the OBD reader not reading anything but the scanner is reading all kinds of codes. I'm using a Foxwell nt501 scanner made for GM trucks

What I have done so far:
- changed out the spark plugs and wires.
- changed out the body throttle and (relearned it to the ECM with a scanner)
- checked the vacuum system by pushing smoke through the system with a smoke machine and I sprayed carb cleaner around the hoses and found nothing.
- changed out the exhaust manifold gasket only because I had to replace the oil pressure sensor
- I reset the Alcohol fuel content because it was showing %17

I'm thinking of replacing the VVT next. I want to change out the water pump anyways just because I don't know if it was ever changed out.

Oh yea fyi you don’t need to remove the manifold to change your oil pressure sensor! I did mine in like 10 min including the cleanup.

 

[H2oboyz]

A scan tool is not a code reader. The scan tool like the Tech 2 enables you to not only read and clear codes but see live data and with the add of a GM manual you are able to see what the data is reading and find out what is normal and not normal. Did you also do a compression test to make sure all cylinders are firing? If you don't have the tools and the experience then you need to find a qualified technician to find the cause. There is much more to cars than just throwing parts at them as you said. I'm a retired GM technicians and I don't on a scan tool any longer at my age and it's hard to find someone you can trust to diagnose your car correctly. I know the dealership's rates are crazy but sometime it's the only way to fix it right. Good luck your gonna need it.

I use a device called FIXD and it’s great. You can go the cheap route and not pay the premium service but it only does half the options but for 50 bucks it’s work it for the year. It scans the vehicle. It defines the codes and explains what they are and what they do for the car. It gives you a price analysis of how much it will cost to repair it if you go to a mechanic it also gives you the do-it-yourself instructions to repair it yourself. If you want it gives you real time information and you can choose anything any sensor or any part of the car that you want to monitor in real time. It even has this neat little function where you can test your car to see how long it takes you to go 0 to 60. It’s great. I highly recommend it !!

 

[H2oboyz]

I use a device called FIXD and it’s great. You can go the cheap route and not pay the premium service but it only does half the options but for 50 bucks it’s work it for the year. It scans the vehicle. It defines the codes and explains what they are and what they do for the car. It gives you a price analysis of how much it will cost to repair it if you go to a mechanic it also gives you the do-it-yourself instructions to repair it yourself. If you want it gives you real time information and you can choose anything any sensor or any part of the car that you want to monitor in real time. It even has this neat little function where you can test your car to see how long it takes you to go 0 to 60. It’s great. I highly recommend it !!

Oh yeah, and it also monitors your maintenance schedule and remind you when it’s time to do certain maintenance on your vehicle. It gives you a list of what needs to be done and how to do it how much the parts will cost or if you had it done in the shop how much it’ll cost it’s an amazing Product and it all goes through your phone on an app