How do these logs look?

B6/7 S4/RS4
#1

Some of you might remember I made a thread a few months ago about some knock issues I was having. On and off I’ve been trying to isolate the problem but not much has changed. I’ve replaced all of the knock sensors, put back in a stock intake manifold, and replaced all of the gaskets, new pcv, etc. As for mods I’ve got everything but JHM’s ported manifold–Headers, FI exhaust, pulley, tune, intake spacers, CM FX400 w/ LWFW, etc.

From what I understand it seems as though the car is running very very poorly right now. I’m running out of ideas on what the problem might be.

LOG-01-003-020-026.CSV (2.17 KB)

LOG-01-003-023-027.CSV (2.13 KB)

#2

alright so the MAF reading looks good at 300+ g/sec (car is pumping the air well, as to be expected with headers etc)

rpm/sec is decent but not what is should be

what jumps out to me is the timing goal… if you notice the numbers look good but the unit is degrees ATDC… ie degrees retarded… every other log I’ve seen has this in *BTDC or degrees advanced… and then on top of that the ECU is retarding timing even more

making a graph

#3

http://img812.imageshack.us/img812/3850/timingcompare.jpg

you can see your timing retard is about the same as mine… but the curve thats being used is going the wrong way.

I’m not sure what to think, the only time I’ve ever seen my Audis have a timing curve set retarded is when I had a small vac leak on my S4 (grind mark on the head)… but it was at most maybe *10 ATDC

hell they look like mirror images, this is very strange… hopefully CountVohn will have some input on this

#4

Yeah I know something really weird is going on here but I’m completely stumped at this point. I just replaced all of the O rings around my injectors, and swapped out the IM gaskets. No vacuum leaks anywhere. The only thing maintenance wise I haven’t done in around ~25k miles now is the fuel filter, but that should be irrelevant to this issue.

I’m starting to believe that this is an issue I might have had before I installed the headers and clutch. Based on past performance it seems my car should’ve been faster. But I never drove anyone else’s S4 with the same mods, nor did I have a vag com to take logs so I never thought much of it.

Beem–Could you expand more on the vacuum leak prob you had on your car?

Happy Holidays everyone!

#5

I really don’t know what to think, if its really running the ignition that retarded its completely inexplicable.

For my vac leak basically when I had my intake ports opened up for the JHM ported intake manifold (this was before the tapered spacers) there was a small grind mark on the mating surface of the head that didn’t get sealed by the gasket. It was super small, and made this loud whistling sound, but was so small that it didn’t trip a lean code.

I took my car to the track opening day and knocked out a 13.9@99.9mph with a 1.80 60’ and solid shifts… I was expecting a low 13@105+ so I knew something was up. I did a few logs and my RPM/sec was garbage, like 480. I used some red rtv goop to seal everything up and did another log, and it bumped it up to like 525rpm/sec… never got back to the track (RIP Black S4), but long story short the tiny vac leak was killing me.

Part of the shit performance was the timing curve my car was using… like -8* at idle and peaking at like 10* under full load. The bosch ECUs are too smart for their own good, so it kept the car running perfectly smooth, but did so on a super safe map.

So one thing I’m trying to investigate is the repeatability of the retarded timing curve with vacuum leaks.

I’m stumped with this though, the whole mirror image deal is just very strange. PM CountVaughn on here and email V8@JHMotorsports.com with these logs and that graph I posted.

And just to confirm no DTC’s under the engine module?

#6

also any issues with your fuel pump? I’d do the filter asap and also log the fuel blocks…

I’m thinking if you are running super lean the ecu is gonna pull the timing wayyyy back to protect everything.

-Maybe pull a spark plug or two and check them out (super white would be lean)?
-Replace fuel filter
-Log fueling blocks (I’ll look up the ones to log for you)
-Install fuel pressure gauge to make sure its keeping up
-Replace fuel pump/lines

block 031 for fuel… so try 1 log of 003, 020, 031 if you can

#7

No issues with my fuel pump that I know of, and the car throws 0 dec in the engine module. Is there an updated part number for the fuel pump? I have replaced the fuel filter before, so it shouldn’t be that bad but I’ll order another one tonight. I just replaced the plugs a few thousand miles ago with Bosch 4417. IIRC the plugs may have looked a little white but nothing crazy–keep in mind I was running around with a pretty bad vacuum leak for a while.

Your track story is interesting…When I first picked up my car I went to the track and put down similar times. Back then I had downpipes, catback, tune, pulley and intake spacers. But my clutch was slipping so bad I only got in two runs before I quit. At the time I blamed the slipping oem clutch.

I’ll take some logs of the fuel trim later tonight and forward the thread to V8@jhm

#8

Attached are logs of banks 003, 020, and 031. I don’t really know much about interpreting logs related to fuel trim so…

LOG-01-003-002-031.CSV (2.36 KB)

#9

A few things to think about. The CM FLFW is a cheap and is prone to fail there was another member that had one of these on his car and he had bad timing issues as well his clutch masters clutch never held up and when he switched over to a Full JHM clutch and flywheel the issue went away . A third guy had same issues also fixed after his CM clutch failed to hold the power. I don’t know to say much past that. Maybe the harmonics are bad in what they sell.

Also didn’t you have a issue with you having a fault code for a knock sensor and the corresponding sensor was in a position that didn’t seem to match up?

Something is going on to have your car telling the request to go negative. I can tell you its going to have to be hardware related somewhere. Even with all the issues Ive seen with the CM units I don’t think this can all be attributed to that

#10

I’m starting to believe that there has been some issues with this car going on for quite a while now. The only time I ever took it to the track (summer '09) I ran high 13’s and trapped IIRC ~100 mph. I didn’t think much of it at the time because my oem clutch was slipping so bad. And at that time I had the tune, pulley, intake spacers, FI downpipes/exhaust, etc. So for the moment I’m hoping I can rule out the clutch/lwfw.

The fault code I was getting over the summer was for knock sensor #1. (P0327 lower limit exceeded) I unplugged and cleaned the knock sensor connections and I haven’t had the code come back since then.

#11

I would have to agree with you. There is something missing here.

The log you just posted didn’t look anything like the one Beemercer posted a graph of. Ill have to go back and look at that one. This log looks great. Looks like the ECU is doing very well. It just seems that the car isn’t doing what you want it to do. The acceleration on this log isn’t of what you would see with headers. I just loged my header car the other day and Im well faster then you.

Still most of your numbers look the same as mine. IE. Timing and fuel.

#12

the RPM/second isn’t very strong. 525 avg from 2000-7000 is ok, but not for a full bolt ons car with headers. My B7 S4 with full 2.5 catless, a fresh tune (JHM updates the tune all the time so you want to make sure you have the most up to date one) in cold temps with 94 octane Sunoco pump was up around 550rpm/sec average.

Maybe i missed it, but can we clarify the conditions you logged in? You’re in Florida right?

octane
temperature/DA (if you know it)

#13

So overall the logs of the fuel trim look ok? The temp when the logs were taken was about 40 degrees. Altitude is about sea level. Only 93 has ever gone into this car, and only from Shell, Exxon, Sunoco or BP. This particular tank was Exxon. For some reason all of the Sunoco stations near me stopped offering 94 so I never got the chance to run higher octane.

Would it be worth it do have a leak down/compression test done? Is it possible that any of this is related to timing components?

#14

Even the other logs looked good. The ADTC note clearly isn’t the actual reading as the car would have performed much different and the logs would have shown up different.

Tune wise the car looks real strong. The headers and exhaust are doing there job. The correction levels are down and the car seems to be humming along. There is a little bit of a timing stumble but thats normal with a CM FW.

From a log output standard the car looks strong and looks like its running great. From a acceleration point of view the car seems to be down on its acceleration numbers. The header cars with your numbers are well faster then what your seeing.

Its always a good idea to do a leak down and comp test in situations like this. That would be a good place to start. While logs are always nice they are just putting you in a direction. Mechanically the car should have a once over as your definitively behind the point of where you should be per all the other cars with your mods.

#15

Bump!

Having my car leakdown/compression tested within the next few days. Anything else I should check out/log while I’m doing this?

I’ll update the thread again once I have all the numbers

#16

Looking forward to the results. Good luck man!

#17

The comp tests and leak down tests should help uncover some answers

#18

Yeah, I have a feeling everything will come back normal though. Sorry for the delayed update. I had a problem with shipping when I ordered the parts I needed for the test. Now that everything is here I should be able to provide an update tomorrow.

#19

So I finally got a chance to compression test my motor yesterday. Here are the results:
Cyl #1: 165 psi
cyl #2: 166 psi
cyl #3: 155 psi
cyl #4: 168 psi
cyl #5: 161 psi
cyl #6: 157 psi
cyl #7: 159 psi
cyl #8: 162 psi

In retrospect I should’ve disconnected the air box elbow from the throttle body to make sure the TB plate was opening all the way. This is a dry test btw, from what I understand I shouldn’t need to do a wet test unless something looks suspicious. I could be wrong but it seems like everything is within spec for a motor with 71k. Keep in mind my motor burns very little oil ~1qt every 3k miles or so. If these numbers look horribly wrong I could always just run another test.

I attempted a leak down test but had trouble getting the motor to TDC. Is there an easier way other than rocking the car back and forth? There’s more than one bolt on the crank. Also my spark plugs had a little white residue on them, nothing major but more than I had expected. I did however change my fuel filter yesterday morning if that means anything.

#20

^damn, very strong numbers, isn’t your car an 04? Yea id say you have no reason to do a leak own test. It’s nice to do while you’re in there, but mainly as a follow up when something looks off. People more so do dry and wet to see how things are sealing up, but with your numbers you should be strong either way.