lots of knock still, am I running lean? Log

[decathect]

See my log here: LOG

Its not pulling right. I'm getting all kinds of erratic knock. One pull will feel fine, the next pull will feel like i'm towing a trailer.

How do my O2s look? Am I lean? What voltage represents 'stoich' on the stock O2? I realize its not valuable for much other than that.

THanks!

 

[habitatguy187]

I'm having problems viewing your log, try following this, it's not too hard just take your time and read it.

http://www.dsmtuners.com/forums/art...st-logs-so-people-can-actually-read-them.html

 

[bboyalan]

After reviewing your log, I believe that you either have "phantom knock" or are suffering from "partial throttle knock." Your fuel trims are fine though, so I'm a little doubtful that it's a bad FPR causing the part-throttle knock. Your low fuel trim is ranging from 104-110, so it's just a little lean but nothing significant or serious. It might be your fuel pump not receiving adequate and consistent voltage too.

I've also attached an o2 conversion table to help give you a general idea.

~AL

 

[decathect]

crap, i posted the wrong log. I'm sorry, here's the right one:
52209.xls

thanks for the suggestions bboyalan. I'm starting to suspect my fuel pump/wiring as well. Might be time to try rewiring it. Out of curiousity though, why does the fuel trims tell you that the FPR is probably fine?

 

[bboyalan]

You're very welcome! I reviewed this log as well. Your fuel pump is either under-performing or you have an old, clogged fuel filter. Almost every time that you went part-throttle, your FTO2's shifted from the 110-120 range into the 120-130 range meaning that the ECU had to add fuel for what it determined as a lean mixture.

To answer your question, I know that your FPR is still doing its job regulating because your fuel trims aren't pegged down to ~81% or so. When that happens, the ECU is trying to pull as much fuel as possible because there's an unregulated excess of it.

 

[decathect]

Perfect. Thank you for explaining it so clearly. I will look into a new filter and pump!

One other quesion though...

I'm still getting knock at 100% throttle... and in that scenario the FT02's still look fine. What would you say about that?

Its weird, I had 2 points where I reach 100% throttle, one time I maxed out the knock at 43 counts, and had very little timing advance. The next time I had less knock, and a bit more timing advance. What gives?? This is confusing me.

 

[bboyalan]

Np! I was actually looking at that. I am thinking that either your intercooler was heat-soaked by then or you need to richen your A/F. IMO, 0.92V is somewhat lean especially at WOT, but I remember you stating that your car is bone stock. I personally tune for ~0.94-0.96V.

 

[decathect]

Np! I was actually looking at that. I am thinking that either your intercooler was heat-soaked by then or you need to richen your A/F. IMO, 0.92V is somewhat lean especially at WOT, but I remember you stating that your car is bone stock. I personally tune for ~0.94-0.96V.

you'd think if 0.92 was too lean, that the FT02s would be higher, though. Any idea what other people get for FT02s under WOT?

 

[bboyalan]

you'd think if 0.92 was too lean, that the FT02s would be higher, though. Any idea what other people get for FT02s under WOT?

Ah, there is a reason why your FT02's and high fuel trims are negligible during WOT; your ECU functions in OPEN-loop mode. It doesn't provide any correction in fuel through its o2 sensor readings. Instead, it uses everything else - MAFS, Knock, MAP/MDP, etc. This is why people tune w/ S-AFC's because it intercepts and modifies that air flow signal that the ECU uses to determine how much fuel to inject. I hope that clears things up a bit

 

[decathect]

Ah, so all we really have to go by is the O2 voltage in that case?

I've also been thinking that maybe my MAF is suspect.

 

[bboyalan]

Yes, that's pretty much it. Sadly, the NB o2 only reads 0-1V compared to a WB's 0-5V range. If you were planning on tuning, you would also pay much attention to pulled timing, knock [obviously], IDC's, and so forth.

You could try cleaning your MAF w/ electronics cleaner or swapping with someone that you know. I believe that there is an ohm test for it too.

 

[decathect]

now, if only i could get the damn fuel line fitting off the fuel pump cover... urgh.

 

[bboyalan]

I believe that there is another fuel line fitting if you trace it down under the chassis. I found it easier to remove it there. Try some good ol' pb blaster too!

 

[bluegs03]

quick question does your knock sensor have black goo seeping out of it? Usually the 43 counts of knock means the knock sensor is on its way out or is faulty.

 

[decathect]

Ok, update on this.

I overhauled my fuel system. I cleaned the injectors, replaced the fuel filter, and upgraded the fuel pump to a walbro. I also replaced the turbo/manifold gaskets, fixed a few exhaust leaks. However, the knock was still there, still killing my performance.

So I had an inclination. The car make a decent amount of noise, lifters and whatnot. I also noticed (according to just the stock oil psi gauge) that the oil pressure was a bit low. So I put some higher viscosity oil in it to see if that would quiet it down. It seemed to work, for a while, car didn't seem to be registering any knock. Unfortunately my datalogger wasn't working at this time so I don't have a log of it.

However, after just 800 short miles, its back in full force. I'm about to go insane. The car *shouldn't* have any boost leaks... I even replaced the O ring in the compressor housing of the turbo. The car might be running a bit rich now, due to the aftermarket pump, but my gas mileage is about the same (22-23 mpg in the city with a good amount of beating on it). I am planning on getting a real oil psi gauge installed so I can see the actual oil pressure.

I'm pretty stumped now though. I'm completely on the end of my rope, I have no other leads to follow.

Here is my most recent log, as you can see, the knock is largely part throttle, but very sporadic.
LINK

Help?

 

[decathect]

oh, and I also tried a half tank of 100 octane... no noticeable difference.

 

[bboyalan]

You should install an AFPR ASAP to help control that higher flowing fuel pump. According to your low fuel trims, the ECU is pulling as much as it can [pegged down to 81.1%]. It can also be contributing to partial-throttle knock because the stock FPR is unable to keep a stable fuel pressure. I personally have dealt with an overrun stock FPR and partial-throttle knock simply from a hot/rewired stock fuel pump. The problems were gone once I installed an AEM AFPR. This was before I upgraded and tuned.

Short Version: If you're running a larger-than-stock fuel pump, you've hot-wired your fuel pump, or both, your OEM fuel pressure regulator is not likely to be keeping your fuel pressure constant as you drive your car. A constant (differential) fuel pressure is an important factor in your ECU's ability to properly control your fuel injectors and deliver the correct amount of fuel to your engine. If the ECU delivers too much or too little fuel to your engine, it can cause drivability problems, poor gas mileage, and even engine damage. As much as possible, you want your fuel pressure to remain constant across the whole range of engine operating conditions.

 

[decathect]

i kinda doubt i'm getting lean knock due to that...