|
prj
|
 |
« Reply #30 on: February 14, 2022, 12:44:14 PM »
|
|
|
Does not matter, it is visible from log already where the problem is.
Do the EGR just in case, but issue looks to be low boost request, and it is following the high altitude map.
This of course causes lower MAF values and then smoke limiter limits your IQ.
Everything else is running full tilt. If this is the case you need a new ECU and clone it via connector (real tools) or via BDM (clone tools).
Try to find and see if baro pressure is jumping to silly values when you are losing power, this is a common fault on these ECU's.
There's no limp mode on ECU side here, as torque request is fine all the time.
|
|
|
|
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #31 on: February 15, 2022, 03:33:35 AM »
|
|
|
ok EGR block off done, still the same.
Logged atmospheric pressure and its at 958mbar (we are at sea level), checked the RS6 and its at 970mbar so a slight difference..
Tried to find EGT but the MVB that has intake, coolant and oil has fuel temp and no EGT will carry on looking.
Going to pressure test the intake as well a bit later.
|
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #32 on: February 15, 2022, 06:22:12 AM »
|
|
|
Log the baro pressure when you have a power cut.
It's clearly an intermittent issue, there is zero point looking at values when the issue is not present.
|
|
|
|
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #33 on: February 15, 2022, 06:38:10 AM »
|
|
|
Log the baro pressure when you have a power cut.
It's clearly an intermittent issue, there is zero point looking at values when the issue is not present.
I did look at atmospheric before and after the power cut and it didnt fluctuate it was at 958mbar the whole time..... I just pressure tested the intake and there was a slight leak from somewhere on the egr valve/cooler so I have now blocked off the egr pipe after the throttle body and pressure tested again no leaks but the issue still persists. I seriously doubt this is an ECU issue as the ECU came out of the parts car which was running fine. I dont know where to go from here. |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #34 on: February 15, 2022, 08:30:23 AM »
|
|
|
Do confirm - there are absolutely no codes on the car, right? I mean precisely zero. You are not filtering them and thinking "ah, this is not important"?
Also log the fuel temperature when it's doing it.
|
|
|
|
« Last Edit: February 15, 2022, 08:32:43 AM by prj »
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #35 on: February 15, 2022, 09:15:44 AM »
|
|
|
The only other code is on the air suspension with a overheat and it turned off. I think I have managed to find egt mvb it's 35 or 41... I will log fuel temp in the morning but last I looked it didn't go higher than 90 degrees
Sent from my EML-L09 using Tapatalk
|
|
|
|
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #36 on: February 15, 2022, 09:16:47 AM »
|
|
|
What should I be looking at for injector quantity?
Sent from my EML-L09 using Tapatalk
|
|
|
|
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #37 on: February 15, 2022, 09:20:37 AM »
|
|
|
I think I posted the full fault scan in my 1st post, I will rescan in the morning.
Sent from my EML-L09 using Tapatalk
|
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #38 on: February 15, 2022, 10:22:26 AM »
|
|
|
The only other code is on the air suspension with a overheat and it turned off. I think I have managed to find egt mvb it's 35 or 41... I will log fuel temp in the morning but last I looked it didn't go higher than 90 degrees
Sent from my EML-L09 using Tapatalk If fuel temp is 90 degrees then there's your fault, replace the sensor. It should never ever be above 30-40 degrees in normal circumstances. Anything over 72C it will start cutting power. Air suspension overheat means you have a leak, this is causing the compressor to overheat trying to keep up the pressure. If you don't fix it, then you will need to replace the compressor on top of fixing the leak. |
|
|
|
« Last Edit: February 15, 2022, 10:25:05 AM by prj »
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #39 on: February 15, 2022, 10:24:12 PM »
|
|
|
Logged Temps this morning while my other half drove the kids to school, fuel temp stayed in the 70s and was 80 degrees by the time we got home, mvb 35 which I think is egt highest was 400degrees..
Will add the log and the full autoscan shortly.
I haven't changed the fuel temp sensor yet.
Sent from my EML-L09 using Tapatalk
|
|
|
|
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #40 on: February 15, 2022, 11:05:53 PM »
|
|
|
autoscan and logged temps (not a 3rd gear wot log, just normal driving), ignore the lambda fault this is the lambda I swapped over from the other car and it was logging this same fault in the other car.
|
|
|
|
« Last Edit: February 15, 2022, 11:18:34 PM by airtite »
|
Logged
|
|
|
|
|
airtite
|
|
« Reply #41 on: February 15, 2022, 11:59:06 PM »
|
|
|
FIXED!!!
Fuel temp sensor..... of all the things. Obviosuly I had no idea what the limit of the fuel temp was meant to be but its a lesson I will never forget. New sensor sits at 54degrees and doesnt really change much a degree here and there..
Now onto troubleshooting the adapative air suspension overheat issue, the car isnt loosing height and the dash lights dont show it going up or down so whatever leak it is cant be that bad but again this will be a 1st for me, all my previous audis have all had normal suspension..
Thank You very much for your assistance PRJ
|
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #42 on: February 16, 2022, 01:45:05 AM »
|
|
|
You're welcome, yes it has "virtual fuel temperature".
You need to rev the engine above 2500 rpm to start seeing the real temp.
If the fuel sensor is knackered just enough it will just limit TQ and not throw any codes.
If it's sitting at 70C all the time at low RPM it's 100% damaged.
It's a matter of figuring out which sensor is sending the bad signal and causing the torque limit.
With the real limp mode you don't have any power at all, like you can't even go over 3000 rpm.
For air suspension get your soapy water spray bottle out.
It doesn't have to lose height, probably the leak is not very bad, but this code 99% of time means it has a leak.
It is very rare for the compressor to go bad and start overheating if there is no leak.
|
|
|
|
|
Logged
|
|
|
|
|
aef
|
|
« Reply #43 on: February 16, 2022, 08:29:27 AM »
|
|
|
great writeup, i learned alot. thank you prj for taking the time for this walkthrough
|
|
|
|
|
Logged
|
|
|
|
|
