I’m talking stock and modded. The sound exists for both.
Mine rattled stock and rattles now. I was told it was normal too.
This was the post making think leak. Rich one side lean the other. Glad it’s as easy as changing the connectors around for you. I don’t know about your car but mine is colour coded. Red is bank 2 and black is bank 1.
So the front O2 sensors were actually properly connected during the clutch install. Had the shop swap them around and my car went into limp mode. Went right back haha that scared me for a second. So the cause of those O2 sensors are unknown at this point.
Back to the fluctuating idle issue, mostly taking notes so I don’t forget, but any ideas would be appreciated.
Watched fuel trim numbers on both banks while spraying around the intake manifold and other vacuum areas. I did not notice any significant fuel trim changes while spraying, but the numbers were constantly up and down on both banks so I could have missed it.
What I did notice: Fuel trims for Bank 1 was -0-8% and Bank 2 was +0-8%. Does this coincide with the O2 sensor codes I saw recently?
Going to check voltage readings on all the O2 sensors and start swapping them around to see if the fuel trim values change banks.
Logging block 33:
B1S1 shows lambda control going way negative, between -8.6 and -23.4. Isn’t that way out of spec? The voltage on B1S1 during that logging period was 1.58-2.03.
B2S1 shows lambda control -1.2 - +13.3. Voltage was 0.98-3.54. I gave it some revs during this period so that would be why it went high on both values.
Codes popped up again this morning, cleared them and the idle fluctuation immediately became less severe. I guess that’s because it reset the LTFT. Drove the car for a while and the fuel trims became progressively worse.
The large fuel trims are not just happening at idle, but all throughout the power band. B1S1 is now pulling fuel where as last night it was adding fuel. B1S1 trim delta from 0 is way more than B2S1.
I’m starting to lean towards a fueling issue. I started using the 0% ethanol 93 exxon fuel a few weeks before this behavior started. Perhaps the injectors got too used to all the detergents in the shell 93 and shat the bed or got some carbon clogging them up.
I guess I shouldn’t count out one of the fuel pumps as the culprit in this case. Is there any way to test them for proper flow?
Well apparently the REAR O2 sensors were crossed. Jake pointed this out so thanks for that. This took care of the codes and the crazy opposing STFT readings.
I also have reliable LTFT data to go off of now, which is showing +6% on bank 1 at load and -1.2% at idle.
STFT bank 1 is constantly fluctuating +/- 5%
If a vacuum leak was causing this wouldn’t I see positive LTFT @ idle? Or am I misinterpreting how LTFT is calculated on Audis?
So sorry I meant to reply like 5 times ago. Good to see you got the inssue all sorted out. It would have taken a lot of work to find the crossed wire issues.
The range of the bank to bank LTFT is best started by checking the instant fuel correction data on each side. To have one side +6 and the other -2 is a little out of range but can be effected by a large amount of things. The 02 age being one of them.
Good news, injector flow rates were all over the board and the filters were clogged with sludge. I will have them back in the car tomorrow or Friday so we will see.
Who did you have test/clean them?
How long did RACECITY take?
What’s the process?
What’s the cost/injector?
Thanks
It would have a been a 2 day turnaround but he didn’t have enough of the lower bushings for our injectors so he had to order more. It ended up taking 4 days with the shipping time for the additional bushings.
Cleaning process is detailed at http://www.racecityinjector.com/fuel-injector-cleaning-process/
He charges $22/injector. Normally you just ship to him but I’m local so I just dropped them off with him. Details are on the website.
Edit: $25/injector for ours since they are DI
Did you consider buying new injectors and selling these ones?
Yeah but I didn’t want to spend $800+. I have another vehicle so it’s not an issue if the car is down.
So here are the before/after flow results of my fuel injectors. Looks like 2 of the injectors were doing pretty poorly for flow and spray pattern.
http://i.imgur.com/Moyirs0.jpg
The guy said the sludge in my filters seemed unusual to him, but he mostly works on marine engine injectors so this might be normal for GDI fuel injectors. It almost sounds like carbon buildup INSIDE of the injectors. Which I don’t know how that would be possible… Maybe I just ran into some filthy fuel? I did notice on one of the injector ports there was a light layer of what looked like carbon which made it very difficult to remove the injector. I’m going to replace my fuel filter and cut open the old one tomorrow just to see if there’s anything funky in there.
One thing I ran into while removing the injectors was MORE FUCKING WALNUT MEDIA. Almost every injector I removed pulled out a fair amount of walnut shell media with it. Shop I paid $800 for a carbon clean: Thanks again for just spraying walnut media all over my fucking engine bay and not bothering to clean it up. I have found more of that shit every time I’ve opened the hood since they did the carbon clean service. I’ve had to stop and vacuum shit every time I’ve pulled the intake manifold to prevent the walnut media from going in my intake valves. I even found it in my spark plug ports when I checked them. Just blatantly fucking careless and it makes me want to never go to that shop again. Well I found what I think was the last pocket of that shit behind the oil filter housing line thing so hopefully I won’t see anymore of it.[/endrant]
MMMMMmmmmmmmmm clean injectors
Well you spent what… 250 including shipping? And you car is down 2 to 4 days while that happens?
My question was did you consider buying new and selling your old ones. Not buying new and throwing the old ones in the garbage.
I. E. Sell 4 each to 2 a4 owners for 300 a set. 600 bucks.
Net cost to you for brand new injectors = 200
Zero downtime
Not sure if that’s accurate pricing on the used market value
Yeah I considered it but didn’t want to deal with selling the injectors. The guy who performed the service is local so I spent $200, no shipping. Down time wasn’t a problem and it gave me time to do some other things I’ve been wanting to do:
- Installed 1/4" npt pipe plugs in the intake manifold runners(instead of the freeze plugs)
- Deleted aux radiator
- Removed airbox flap and routed brake duct hose to the inlet
- FINALLY aligned the bumper
nice. I’m thinking for me or other people…what makes more sense
maybe jake@JHM would know whta the market is for the big injectors