What is normal to see for both short and long term fuel trim?
Right now what I am seeing is STFT looks fine in my opinion. But LTFT looks a bit high to me. Both banks are at a consistent 14%. Thoughts?
how does the car run otherwise? Have you ever done anything with your injectors? Is the ECU logging any misfires?
I had an issue where my trims were in the teen% and I ended up having a bad injector in cylinder 8. It was causing that bank to run lean and was adding fuel to the cylinders on that bank to compensate.
What groups are you monitoring to get these values? In case you were not aware, these are considered quad “banked” engines and you need to check both engine modules in order to get all of your STFT & LTFTs (4 of each)
So, there was a code that was hidden from previous owner. Emissions bank 3 sensor 1 heater circuit open and 02 sensor circuit open. Could this be part of all of the problem?
14% is not very good. That means the car is adding 14% fuel.
If I get a chance this weekend I am wanting to pull the intake off and see if I can get a better look at fuel fittings and injectors to make sure nothing is leaking.
Trust me, you would know if there is a leak. The high side fuel pressure is about 20 bar or 290 psi at idle so it would be a massive leak!
Most likely you have carbon buildup on the intake ports and valves causing the air to not go into the cylinders correctly and/or fuel injectors that are not spraying the fuel into the cylinders correctly from a clogged filter and/or carbon buildup blocking the ports of the fuel injectors.
So how can I check injectors? And I did a carbon clean about 3k miles ago how do I go about checking filters and injector health?
How many miles are on the car… When you did a carbon clean did you service or do anything with the injectors. If you got bottom of the barrel replacement injectors from Rock or one of those parts houses then this would make sense. As some of those injectors while the same base model injector are not usually the same flow specs as the genuine Audi ones.
I have personally never done anything to injectors. I’m going to stop by audi tomorrow and see if I can get them to give me service records. The car has about 118k miles
Just to add some info… I got some cleaned /flow matched injectors from the JHM program and one of them died in less than a year. I fought it for awhile convinced that I couldn’t have had an injector fail that soon.
People have had the budget injectors and installed them and had them go back right out the box.
Remember cleaned flowed and serviced is 9/10 the best way to go. Now in the past if your injectors had damage that was caused by carbon build up and the service and cleaning helped bring them back. That’s a win but once the injectors fail they fail. It’s a hard call.
Given the fact that brand new budget injectors don’t flow consistant and they tend to flow less than the OEM Audi injectors. For the cost it’s worth just getting your current working injectors serviced and down the road if one dies replace it but replace it with the OEM units not the cheaper brands.
Updated on the fuel trims. I added a good injector cleaner to a half tank of gas and have ran about half of that and my LTFT has come down to about 12% now
Any misfires ?
Just on cold starts. Today I got a lean code though p1086. And really rough idle
Update, while doing my yearly intake check and finally epoxy my flaps. I found 4 broken flaps on the same side. And after getting them to all take the same path my LTFT has made it to 0 now.