P1136 & P1138 Issues
#31
04-17-2014, 05:26 PM
NEW O2 Sensors
NEW Intake Manifold Gaskets
NEW Injector O-Rings
I installed the above items but I still have the fuel corrections at idle on a cold start. The fuel corrections go from 10-12% down to 0 or negative once the car reaches 60-90 degrees. You can see the change start happening in my log file around ROW 545.
Any ideas on what could be causing the addition of 10-12% fuel only at idle until the car warms up? The car is also very lean on a cold start sometimes, Block 031 shows Lambda at ~1.3-1.4 during the high idle cold start, then it settles down to 1.0 when the RPMS drop. I have no secondary air injection codes but I think it's broken, I can't hear or feel it working, not sure if that could be causing this.
LOG FILE
https://docs.google.com/spreadsheet/...mc&usp=sharing
NEW Intake Manifold Gaskets
NEW Injector O-Rings
I installed the above items but I still have the fuel corrections at idle on a cold start. The fuel corrections go from 10-12% down to 0 or negative once the car reaches 60-90 degrees. You can see the change start happening in my log file around ROW 545.
Any ideas on what could be causing the addition of 10-12% fuel only at idle until the car warms up? The car is also very lean on a cold start sometimes, Block 031 shows Lambda at ~1.3-1.4 during the high idle cold start, then it settles down to 1.0 when the RPMS drop. I have no secondary air injection codes but I think it's broken, I can't hear or feel it working, not sure if that could be causing this.
LOG FILE
https://docs.google.com/spreadsheet/...mc&usp=sharing
Last edited by Rn3037; 04-18-2014 at 04:57 PM.
#32
04-20-2014, 07:39 PM
MAF UNPLUGGED RESULTS
The MAF that was currently in this car was from my 2006 A8L that had no issues. Also note, the car ran exactly the same with the MAF unplugged because when I plugged it back in, the RPM and engine sounded the same.
***Air Fuel Lambda was on the rich side then the O2's corrected up to NEGATIVE 25%
***BLOCK 107 PASSED! Any ideas on what is causing this behavior?
The MAF that was currently in this car was from my 2006 A8L that had no issues. Also note, the car ran exactly the same with the MAF unplugged because when I plugged it back in, the RPM and engine sounded the same.
***Air Fuel Lambda was on the rich side then the O2's corrected up to NEGATIVE 25%
***BLOCK 107 PASSED! Any ideas on what is causing this behavior?
#33
05-17-2014, 04:57 PM
*FIXED*
Used smoke machine at my local mechanic shop, big leak on the valve cover gasket. The stupid thing about this is that I actually did the valve cover gasket when I bought the car so when I re-installed the gasket I must've 'creased' part of the gasket so it didn't seal. Lesson is ALWAYS look at the simple stuff first and if you 'touched' anything on the car.
Used smoke machine at my local mechanic shop, big leak on the valve cover gasket. The stupid thing about this is that I actually did the valve cover gasket when I bought the car so when I re-installed the gasket I must've 'creased' part of the gasket so it didn't seal. Lesson is ALWAYS look at the simple stuff first and if you 'touched' anything on the car.
#35
05-19-2014, 12:23 PM
Thank you! Yes it was VALVE COVER GASKET so that would basically be an internal air leak on the engine.
#36
08-16-2014, 05:45 PM
!!****FIXED****!!
Mine turned out to be the MAF sensor. It finally gave out. Replaced it with an OEM Bosch unit for $150. Not a cough since. No MIL/CEL. Happy Day ! It must have been gradually fading, as I didn't notice the performance dropping but it definitely was. Power is back with a vengence ! Also noticed the MAF sensor and Fuel Pressure Regulator are different part #s from the A8 same year. Didn't replace the pressure regulator, but I might just as a maintenance item.
Mine turned out to be the MAF sensor. It finally gave out. Replaced it with an OEM Bosch unit for $150. Not a cough since. No MIL/CEL. Happy Day ! It must have been gradually fading, as I didn't notice the performance dropping but it definitely was. Power is back with a vengence ! Also noticed the MAF sensor and Fuel Pressure Regulator are different part #s from the A8 same year. Didn't replace the pressure regulator, but I might just as a maintenance item.
Thread
Thread Starter
Forum
Replies
Last Post
