Stalling when at full stop either in gear or idling on neutral (1 Viewer)

[ranger474]

Mud fam,

Here is situation: my 09 lc200 started to stall when vehicle is not moving either in gear or neutral. It happens intermittently, no codes thrown. I was thinking it was a bad fuel pump and replaced it, issue still exists. No DTC, techstream shows no issues, evap test pass etc...any ideas on what may cause this? Thanks!

 

[KLF]

Low idle?

 

[TeCKis300]

Sorry to hear of your troubles.

Could be multiple things. Without codes, I would generally start exploring fueling as most ignition related faults will show some form of codes.

Are you getting any other symptoms including drivability issues, stumbling ahead of stall, etc.?

There's been faults in the fuel level sender leading to these symptoms before. Basically running out of gas, with the fuel level still shows gas in tank. Does it continue after filling the tank?

There's fuel pump ECU issues where there insufficient voltage at the pump to keep it running.

Or fuel pump as you suspect. I just went through replacing a bad fuel pump in my '09. If you have techstream, take a look at the Long Term (LT) fuel trims in Bank 1 and Bank 2. What do those read? Here's a longer diagnostic thread for the fuel pump

P0171: System too Lean (Fuel Trim)

Working through this and could use the hive minds support. P0171: System too Lean (Fuel Trim). Also P0300: Random/mulitple Cylinder misfire detected. Multiple specific cylinder misfires P030x. Symptoms: In diagnostics after getting home. LT fuel trim on both banks at idle are high. +15 and...

forum.ih8mud.com

 

[ranger474]

600--800 rpm... I'm thinking MAF could be one of usual suspects...then oxygen sensor...maybe EGR valve? Again, no DTC, health check is a-OK

 

[TeCKis300]

600--800 rpm... I'm thinking MAF could be one of usual suspects...then oxygen sensor...maybe EGR valve? Again, no DTC, health check is a-OK

Surely could be any of that. As those govern closed loop fueling, out of range or unexpected signals should usually trip some DTCs.

You can try electronics or MAF cleaner. Oxygen sensors are associated with one or the other bank. So usually you can see some DTC related to a bank if one is problematic or out of sync.

Is this a readily reproduceable problem? How/when does it happen?

Could be a simple battery or grounding issue too. Anything leading up to these problems?

 

[ranger474]

Surely could be any of that. As those govern closed loop fueling, out of range or unexpected signals should usually trip some DTCs.

You can try electronics or MAF cleaner. Oxygen sensors are associated with one or the other bank. So usually you can see some DTC related to a bank if one is problematic or out of sync.

Is this a readily reproduceable problem? How/when does it happen?

Could be a simple battery or grounding issue too. Anything leading up to these problems?

Thank for the insight. It is currently 86 degrees outside, so I disconnected MAF, cleaned it, cleaned airbox, btw the air hose clamp was loose hence the hose, tightened it, then run idle on P for 5 minutes straight and so far no stalls....I'll keep troubleshooting though....

 

[rlynch356]

a leaking hose to the MAF could cause this, especially if it after the MAF.. since the air flow readings would not match what it expects and thus the fuel mix would be too lean leading to stalling.

 

[ranger474]

a leaking hose to the MAF could cause this, especially if it after the MAF.. since the air flow readings would not match what it expects and thus the fuel mix would be too lean leading to stalling.

I truly hope that was the case!

 

[CharlieS]

I'm hopeful your loose intake hose clamp
was the issue and it was resolved.

If you continue to have the stalling problem, one issue that I've experienced with similar stalling symptoms is a failing fuel pump ECU.

 

[ranger474]

Little update: so after taking care of the loose air hose and 40 miles later I had stalled only once. Before I stalled at every traffic light. Fuel trims look fine, again, don't see any issues as techstream shows, unless I've missed something in reading data correctly. I took a snap shot of a screen when truck was running, if you guys see anything iffy in it please let me know! As for now I'll continue monitoring and if it'll keep stalling my next suspect would be PCV valve, then oxygen sensor, then EGR valve and then fuel ECU, kinda sucks to rule out issues one by one without DTC codes....

 

[chilibit]

Has this extended across multiple tanks of gasoline?

 

[ranger474]

Has this extended across multiple tanks of gasoline?

No, on one tank so far.....

 

[ranger474]

Okay, finally solved the issue...When stalled again, finally truck threw a code, yasss! At least that gave me idea and location of the problem. The code was P0113 (intake Air Temperature High Input), so when inspected hose and lines around throttle body, voila! Friggin' fuel vapor feed vacuum line had a crack in it! So quick and easy fix (OEM line at the dealership was $34), and stalling issue resolved. So folks, if you run into similar situation, inspect your vacuum lines!

Cheers!

 

[bloc]

Great tech, thanks for posting follow up

 

[ranger474]