Intermittently working 03 RS6
 

Hi Richard, first off Kudos for answering just about everybody's posts here. Pretty amazing.

I have four Audis, three of which have Aquamist WM injection and all except my newest addition 03 RS6 have been working flawless. All tuned and installed by AMD in Woodinville WA

So I bought the RS6 already built around 3 months ago. Over time a problem has developed where with the meth on the car will run great for about 10 mins and then will just fall flat. No failsafe lights, no other indicators other than no power and the gauge doesn't bar up. The system just doesn't work. Usually I will turn it off so as not to damage anything. This morning I swapped the pump from my 3L S4 which is getting rebuilt and got the same results.

Next up is to check the wiring. Any suggestions as to which wire(s) to focus on? Could it by my FAV? I can swap that as well. AMD swapped the tank filter a few days ago. Didn't solve the problem obviously.

Usually if the car sits a while I can get back in and it works again, for only 10 or so minutes.

Could it be temp related?

This car runs 100%

Thanks
Travis

Re: Intermittently working 03 RS6
 

What is the engine code of this car?

Re: Intermittently working 03 RS6
 

Engine code is BCY

Re: Intermittently working 03 RS6
 

http://www.pbase.com/ocotillo/image/165484569.jpg
http://www.pbase.com/ocotillo/image/165484570.jpg
http://www.pbase.com/ocotillo/image/165484571.jpg
http://www.pbase.com/ocotillo/image/165484574.jpg

Re: Intermittently working 03 RS6
 

Looks quite normal. I can;t quite make out. if anyone of the yellow led is lit on the gauge. Can you confirm.


Can you unplug the water level sensor, run the car for a few days and see if the problem goes away.

Re: Intermittently working 03 RS6
 

Neither light was lit. It's just the lighting. Sorry I didn't clarify.

Re: Intermittently working 03 RS6
 

Today's drive. You can hear knocking that's why I didn't go full throttle. Meth will be off from here on unless you have a suggestion for test or I can get it in to AMD for fix. Car was fine when I purchased it two months ago. Also today was the first time the fail safe lights came on. Bad FAV?
https://youtu.be/O0f2WgcEo1o

Re: Intermittently working 03 RS6
 

Also I will unplug water level sensor and report back.

Re: Intermittently working 03 RS6
 

Your issue is very unusual. Lets see what happen in the need few days with the level sensor unplugged.

From the video, it appeared there was no flow. The failsafe did trigger (top yellow led blinked).

Can you do a "SYS" test instead and see if you see any spray coming out of the nozzle.

questions:
1. Where is pump located
2. What is the water methanol ratio
3. What brand is the methanol used.

Re: Intermittently working 03 RS6
 

Ok, I'm not running the system on since I can hear detonation. I'll try a little bit everyday.

I will do a SYS test but cannot remove the nozzles as they are buried. Can I unhook the tube after the FAV?

Pump is in trunk. I'll get a picture of the setup
Running 100%
I use whatever AMD carries. They have barrels of it at their shop. I'll have to check with Jason

Re: Intermittently working 03 RS6
 

Yes, unhook the tube after the FAV will work as we just want to know if the FAV is oK or not.

If FAV is the issue, we need to look into the purity of the methanol.

Are the failsafe wires hooked up? It should cut boost when it activates.

Re: Intermittently working 03 RS6
 

there is flow after the FAV

Which wires are failsafe? Sorry I didn't install but happy to look.

Made 100mile trip and seemed to work ok for most of it.

I wish you had parts in stock as I would order and start swapping!

What does disconnecting the tank level sensor do?

Re: Intermittently working 03 RS6
 

- Failsafe wires are brown and white
- 100 miles is OK, good.
- We have all replacement parts in stock.
- Disconnect the level sensor stops the system from switching off automatically.

question: did the gauge show flow?

Re: Intermittently working 03 RS6
 

More pics for reference. Hope this helps. Again there was plenty of flow after the FAV.
http://www.pbase.com/ocotillo/image/165491204.jpg
http://www.pbase.com/ocotillo/image/165491197.jpg
http://www.pbase.com/ocotillo/image/165491198.jpg
http://www.pbase.com/ocotillo/image/165491200.jpg
http://www.pbase.com/ocotillo/image/165491199.jpg
http://www.pbase.com/ocotillo/image/165491201.jpg
http://www.pbase.com/ocotillo/image/165491203.jpg

Re: Intermittently working 03 RS6
 

Thanks Richard. Darn it I didn't even look at the gauge. Will do again and report. Was too busy watching it out the window into a bottle

Re: Intermittently working 03 RS6
 

Ok guage lights up great upon SYS test. But when driving it seems to struggle. Maybe car just needs a retune?

Re: Intermittently working 03 RS6
 

system test with the nozzle connected?

Re: Intermittently working 03 RS6
 

Yes just now it was all connected and the bar lights came on car was idling.

Re: Intermittently working 03 RS6
 

Took it out for another spin. System was on but was in traffic. Once I got past traffic system didn't work at all, no giddy up so I turned off. I ordered a new FAV, relay, and C clip to swap in unless AMD can get the car in for a tune up before then.

Re: Intermittently working 03 RS6
 

Your tank system is amazing. Flawless.

Before swapping parts over, need to complete my diagnosis just ion case it is something simple.

Please try answering the following:

1. Does the green led flicker with engine speed when stabbing the accelerator.
2. During a test drive, does the "B" led light up upon acceleration?
3. When the system works, confirm if your see bars going across the gauge during acceleration.

Re: Intermittently working 03 RS6
 

Green light flickers well
B light comes on
Bars work and first and then don't as much

Here's my latest theory............boost leak.
Not as bad as first but once the car warms up whatever hose is leaking gets softer and leaks more. I have had a woooo honking sound and thought it was a bad axle. Swapped in a new axle tonight and that didn't fix the sound so I'm assuming it's a boost leak which I would imagine would cause all kind of ruckus for the meth system.

That tank was built by Jason at AMD. It's a great set up. I have the same in my laser S4 avant.

Re: Intermittently working 03 RS6
 

You could be right.

If you are not building boost, you will not be using a large amount of fuel. Since the aquamist tracks fuel flow, it won't be inject a good amount to build up flow bars.

There is one thing you can try...

Link "FDC". this hijacks the gauge to display Fuel-IDC%. Watch the gauge as you drive. If the iDC is decreasing slowly with time, it might be the issue you are experiencing.

Also a reason why the failsafe is not triggering because aquamist is seeing a reduction of flow vs IDC%, no reason to trigger a failsafe.

I think the "FDC" link will give you a good deal of feedback.

Re: Intermittently working 03 RS6
 

Ok will do this and report back. Thanks Richard

Re: Intermittently working 03 RS6
 

Ok last night I tested the DV's and they seemed ok, not very old based on what previous owner told me. Took it for a freeway spin just now and it pulled really strong at first, lots of bars with the FDC linked. There are a couple good 2-3 long mile hills where I really let it rip. With minor traffic the 1st time it did great but only short pulls. On the way back, same hill, I was able to get into for sustained throttle and that's when I noticed it was a bit weaker FDC read and eventually the throttle cut, even if I downshifted. I would assume this points to a small boost leak that doesn't like sustained boost!? Nice warm day here today. I'll try again tonight or tomorrow as I am heading on another 100 mile work trip. Thanks Richard.

Re: Intermittently working 03 RS6
 

The boost leak could be the problem. This may explain why the FDC get weaker. Aquamist cannot detect boost leak, it just follows IDC%.

Re: Intermittently working 03 RS6
 

Hey Richard, reviving this thread. I have been driving the car since the last post on wastegate boost, which is around 7-8 lbs. Car drives just fine and has decent power. I'm thinking about bringing the meth back on but Jason (AMD tuner) thinks we may have minor piston damage which could be our culprit for the meth system not working properly. Like I said the car runs fine on wg boost, doesn't use oil, and pulls strong. On meth it's supposed to be running 24lbs taper back. I intend to do pressure test and leak down test in the next coming weeks to verify if there is any piston damage. Just curious do you think piston damage could be the culprit? I just don't understand why it runs fine on wg boost but not on the meth system.

Thanks for any input.

Re: Intermittently working 03 RS6
 

if the meth was not working properly, it would trigger the failsafe and drop the boost down to wastegate pressure.

We only make the system, how the system was set up is not under our control.

Re: Intermittently working 03 RS6
 

Hi Richard,

Back at this a bit. Jason says he may have time next week to put the car on the dyno and try to figure out what's going on. Today I swapped in a new FAV and Relay that I ordered last summer just to see if it would change anything. I did some video tonight. Please watch and let me know what you think. Should I check the wiring to the ECU? It just doesn't seem like the meth is kicking in properly. When it's on and low boost it feels fine just when I request anything above 10 or so psi in isn't getting enough fuel/meth.

Thanks and if anything I'll let you know what Jason figures out next week.

https://youtu.be/w0aLu-ZNjDQ

Re: Intermittently working 03 RS6
 

Let me know.

What is the serial number of the controller?