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Small update - spent most of the day yesterday getting a few loose ends taken care of.
First up, brakes. My drilled / slotted rotors were starting to show age and my pads were toast, decided to go with Stoptech blanks & EBC red stuff pads. Rears still have decent amount of life on them so I figured I'd leave those for another day.
Funny ... this is my very first brake change . I've never done pads OR rotors before but it was a lot simpler than what I was making it out to be in my head.
Threw on some fresh high temperature black paint:
End result .. looks so much nicer:
Next up was installing a catch can. Most B5 / Euro / Audi sites online sell these kits for almost $150! I pieced mine together for $45 ...it included a mounting bracket but I ultimately decided against using it.
Stealth AF:
Overall, productive weekend.
All cleaned up:
Currently, I can't throw any more revisions or do any more logging until I get my wideband figured out.
It's reading rich under idle / WOT - I've taken the necessary troubleshooting steps (changing banks, changing o2 sensors, open air calibration / controller reset) .. I'm still getting the same A/F ratio.
Tuner seems to think the controller is not accurate and I should spring for an AEM or Innovate system .. it's another $175 I don't want to spend
If you guys read this ... I do appreciate it and I'm sorry for my long winded posts
Since my last update, I've got the following parts installed:
Inline fuel pressure gauge - this is mostly for troubleshooting my hard starts in the morning and having a visual of actual fuel pressure going to the fuel rail / before the fuel pressure regulator.
If the car sat for more than a day, it would take a consistent 3-4 long starts before the car would eventually sputter to a smooth idle. Kind of annoying but, not the end of the world.
After installing the gauge, the car hits 60 PSI at idle (normal). Interestingly, once the car shut off for more than a day or so .. fuel pressure would slowly bleed out all together. This suggests I have a hose clamp that isn't tight enough that's in the fuel tank. Am I worried about it? Not terribly .. if my car was running extremely lean under WOT then I would be more obligated to fix it.
Workaround - A quick ~1 second turn of a key, followed by an actual start gets the car started more quickly
New AEM Wideband:
I didn't want to shell out another $175 for ANOTHER wideband that was already installed, but my ProSport gauge was off by roughly .5 in both directions .. even with a new O2 sensor / changing from bank 1 to bank 2. For something so critical, I couldn't cheap out.
New AEM gauge reads perfectly - tuner claims it should oscillate between 14.6-15.2 and it does just that
Old gauge was between 14.1 - 14.6.
What does this mean? I can FINALLY start logging the car ... I expect maybe 4-5 revisions on 91 octane before I get the green light to move onward to E85.
I've had a few run-ins with various cars and the S4 made work of all of them:
New-ish COBB tuned STi with exhaust - 3 car lengths from 60-100.
335i automatic coupe - 2 car lengths from 2nd to the middle of 3rd
The torque & highway gearing in the S4 is really fun ... 3rd goes to around 100 and 4th goes into the 125ish range.
Few random pictures:
Here's the daily ... I fucking love this thing . It has only needed an oil change and a windshield fluid reservoir cap - running strong at almost 203k miles.
A friend of mine wanted a few shots of my car before he left for NC ... more photos coming soon:
looking good! I can't wait for an E85 vid! I almost bought the same blue Fit, but it had some rust I didn't want to deal with. The hunt continues. I only want white or blue.
Please keep those wheels. They (and the OEM ones) are perfect for this car.
Thanks Sam!
I love the look ... I may add spacers in the rear but otherwise, what you see is what you get. Very happy with it right now.
Originally Posted by gnuts
looking good! I can't wait for an E85 vid! I almost bought the same blue Fit, but it had some rust I didn't want to deal with. The hunt continues. I only want white or blue.
Thanks much!
The Fit literally feels indestructible.
Pot holes? No problem. Speed bumps? Send it. Oh, you want to no-lift shift and bang on the limiter? Please do. It just ... doesn't care. At all.
Curious, Tyler...do they make a backflow valve for a fuel system like they do for sprinklers?
I recall having to change mine because without suction the water would go back to the canal
and the pump would run dry while trying to siphon the water back to it.
Just an idea. Looks awesome though...I love that you have not given up on this.
Curious, Tyler...do they make a backflow valve for a fuel system like they do for sprinklers?
I recall having to change mine because without suction the water would go back to the canal
and the pump would run dry while trying to siphon the water back to it.
Just an idea. Looks awesome though...I love that you have not given up on this.
You ideally don't want this in a car though. Fuel will not go bad if it's in a high volume (ie gas tank) vs a low volume (ie fuel line). This is why gas in a lawnmower goes bad (~.25gal) but gas in a car (15gal) doesn't.
I was mainly saying it so the line stays primed from tank to the pump...I am guessing that's why he had the 3 or 4 tries before it fired up.
but I guess turning key to ACC to kick pump on before turning over works too.
I was mainly saying it so the line stays primed from tank to the pump...I am guessing that's why he had the 3 or 4 tries before it fired up.
but I guess turning key to ACC to kick pump on before turning over works too.
If the pump isn't priming the line right away (like any other car) there's probably something wrong with the filters or something causing pressure loss in the line. The volume of fuel in the lines isn't much and the pump, especially a higher powered one, should be able to prime the line almost instantly. 3-4 days is about right for fuel to trickle back into the tank though, that's done by design.
Curious, Tyler...do they make a backflow valve for a fuel system like they do for sprinklers?
I recall having to change mine because without suction the water would go back to the canal
and the pump would run dry while trying to siphon the water back to it.
Just an idea. Looks awesome though...I love that you have not given up on this.
You ideally don't want this in a car though. Fuel will not go bad if it's in a high volume (ie gas tank) vs a low volume (ie fuel line). This is why gas in a lawnmower goes bad (~.25gal) but gas in a car (15gal) doesn't.
Actually it right up by the HPFP. They are on all Audis with a Direct Injection Motor.. It is meant to keep the fuel lines pressurized while the car is sitting or when you remove the gas cap.
It's not. The N80 valve is the evap purge valve which is what manages fuel vapor in the tank. It's essentially there to keep "vent" the excess vapor by dumping into the fuel lines to be burned since it can't be vented out to the air.
Originally Posted by 1killercls
Actually it right up by the HPFP. They are on all Audis with a Direct Injection Motor.. It is meant to keep the fuel lines pressurized while the car is sitting or when you remove the gas cap.
No, it's designed to relieve pressure in the tank by burning excess vapor. This is on almost every car on the road today, not just Audi and not just DI cars. There is no check valve between the fuel pump and the fuel rail because you WANT the fuel to drain back into the line. The pump prime prior to the engine firing is what pressurizes the fuel lines. People typically don't let their cars sit for that long though AND, unless there's a leak in the line somewhere, you won't get too much drain back because the system is closed. Sorta like how a straw filled with water will stay filled with water if you keep your finger on the tip. Once you let your finger off, it drains.
Hey...on the hard starts after sitting a while...did you check your N80 valve?
I haven't looked into replacing it, but it started happening the moment I changed out to a higher pressure fuel pump so I think the timing is suspect.
While the pressure does bleed out overnight, I've noticed if I put the key into accessory position, the fuel pressure (before the fuel pressure regulator) immediately hits 60 psi once the fuel pump is primed.
My thoughts are, if the key is in 2nd accessory position and fuel pressure is 60 psi before the regulator ... why would it have trouble starting?
Originally Posted by rockstar143
Curious, Tyler...do they make a backflow valve for a fuel system like they do for sprinklers?
I recall having to change mine because without suction the water would go back to the canal
and the pump would run dry while trying to siphon the water back to it.
Just an idea. Looks awesome though...I love that you have not given up on this.
You know what's interesting is I'm not the first person to have this issue and there's nothing really definitive other than some leaky hose clamps
And thanks J, means a lot man. A lot of busted knuckles later and it's starting to get fun .
Originally Posted by 1killercls
Audi's are a different beast. But after having one for ten years you get to learn a lot!
So, logs don't look the greatest but that's to be expected on a base tune.
My AFRs run real rich, tiny bit of ignition retard, and a tiny bit of knock.
I'm waiting on what my tuner says / what needs to happen to remedy all of this. Hopefully it's all adjustments that can be done on the tune and nothing too crazy on the hardware end
I haven't looked into replacing it, but it started happening the moment I changed out to a higher pressure fuel pump so I think the timing is suspect.
While the pressure does bleed out overnight, I've noticed if I put the key into accessory position, the fuel pressure (before the fuel pressure regulator) immediately hits 60 psi once the fuel pump is primed.
My thoughts are, if the key is in 2nd accessory position and fuel pressure is 60 psi before the regulator ... why would it have trouble starting?
Same question. Sounds like you have pressure at start so there isn't an issue with the line. Can you log start up and send that to your tuner? Maybe the engine is too rich or too lean at start? Injectors themselves good?
Same question. Sounds like you have pressure at start so there isn't an issue with the line. Can you log start up and send that to your tuner? Maybe the engine is too rich or too lean at start? Injectors themselves good?
Running a log while starting is actually a great idea - I'll give that a shot and see if my tuner has any way of making adjustments.
Also .. further reviewing my logs ... car appears to need an alternator.
I'm confident my grounds are tight (probably would not hurt to triple check), but my voltage drops to 11.4v under WOT ... it should be mid 13s at the lowest.
It's not. The N80 valve is the evap purge valve which is what manages fuel vapor in the tank. It's essentially there to keep "vent" the excess vapor by dumping into the fuel lines to be burned since it can't be vented out to the air.
No, it's designed to relieve pressure in the tank by burning excess vapor. This is on almost every car on the road today, not just Audi and not just DI cars. There is no check valve between the fuel pump and the fuel rail because you WANT the fuel to drain back into the line. The pump prime prior to the engine firing is what pressurizes the fuel lines. People typically don't let their cars sit for that long though AND, unless there's a leak in the line somewhere, you won't get too much drain back because the system is closed. Sorta like how a straw filled with water will stay filled with water if you keep your finger on the tip. Once you let your finger off, it drains.
This sounds perfectly fine, but I must ask; I was having trouble with long start up times after refueling and also after the car sat overnight. Why did replacing my N80 Valve remedy the issue and stop the code being thrown?
You poor bastard...I did a VAG.Com check on Sunday...got zip, zero nada. 108k miles, stage one tune. Timing belt and water Pump at 102k. My buddy with a B9 says thats why I have so few problems, I maintain it well and drive it hard.
This sounds perfectly fine, but I must ask; I was having trouble with long start up times after refueling and also after the car sat overnight. Why did replacing my N80 Valve remedy the issue and stop the code being thrown?
04-04-2018, 10:49 AM
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- running strong at almost 203k miles.
