I've just completed my 6-bolt swap and am trying to make sure everything is working proper before I start tuning.
Setup: all stock 93 AWD TSI except for:
- fuel pump rewire
- ported 14b
- Cut air can
- Dejon Tool UICP w/ Turbo XS bov
- MBC
- 2.5" exhaust

I've noticed all three fuel trims are maxed at around 140% but FTO2 sits around the 100% mark which tells me that even though trims are high, I'm not running too rich/lean.
I also did a couple of 2nd and 3rd gear pulls tonight and found injector duty exceeding 110% at ~11psi boost. I used to run 15PSI on the old 7 bolt motor with little/no knock. I am concerned because my injectors seem maxed out but I am running quite low boost.
I've been checking for boost leaks but havn't found any yet. Exhaust is sealed up tight. The only thing I can think of is that I have a bad or clogged injector(s). Could it also be a flaky MAF? (I have a 2g waiting to go in)
I am planning complete fuel system upgrade soon but would like to target problem areas first. Anyone have any thoughts on where to start looking first?

The reason you are lean is because you are venting a BOV and running the stock MAF. You are pulling in unmetered air.

No, I am recirculating.

Ahh, good good.

I would start with the rewire, make sure it's done right. Connect your fuel pump up in stock form, see if your fuel trims change.

Also, what are your IDC's at idle? Did you change anything else? Have you done a boost leak test?

I have done the fuel pump rewire. Used 10ga wire I think straight from the battery (w/ fuse). Maybe I'll recheck all the connections though just to make sure something hasn't started to corrode as it's been a couple of years since it's been done.

IDC at idle seems to be 1% and 2.05ms. Is this normal?

I'm off to Picton this morning for an event so I'll do another leak check tonight. I'm going to keep the boost way down for now to keep risk of serious damage down.

The only other thing I can think of that's changed is slightly ported manifold and O2 housing. Nothing extreme though.
Thanks for the suggestions Ryan.

What the hell? That doesn't make sense. When is the BOV open when the throttle plate is open?

Could be as simple as a clogged fuel filter.

Just got back and was able to log a couple of runs. The duty cycle seems a bit lower but is still hitting >100%. I logged MAF freq. this time and noticed I seem to be frequently topping out at 1604Hz well before redline. As low as 5300RPM and only 55% TPS at times. Is this max for stock MAF? If so, why would I be maxing out so early? Should I switch to the 2g MAF now?

I agree on the fuel filter. I do seem to be limited on fuel delivery, although it was changed less than a year ago. I was reading the SteveTek page and there seems to be a lot of logic there in removing the overly restrictive fuel lines/filter in place of a higher flow system. I may head down that road before fuel pump and injectors.

Anyone have any tips for posting log files (Excel format)?

You didn't max out the stock MAFS - the ECU only shows your logger up to 1604Hz.

How about during idle, vacuum keeps the BOV valve open on some BOV's does it not? He would be sucking in unmetered air and therefore adding too much air to a stoich fuel mixture causing a lean condition.

Doesn't explain the WOT stuff though.

^^^
That would barely explain the low trim, let alone mid and high...

i belive if he's venting he would be running rich not lean

Not if the BOV leaks in vacuum, which the stock one is prone to (or by mis-adjustment of the aftermarket valve).
Then there will be both rich conditions and lean conditions.

Anyhow, lets please stop discussing BOV venting here since Jamie says he is recirculating.



Jamie, have you checked if your O2 sensor is working (cycling)?
A bad O2 sensor or exhaust leaks to throw it off could contribute to your trims being artifically high and you will end up running quite rich.

You could pull the plugs and have a look, to see what is really happening inside the cylinder.

Guys, just to clear things up again, I'm not venting to atmosphere. I am recirculating.
My plan tonight is to swap to a spare ECU I have. I'm guessing it will take a day or so of driving for the trims to stabilize. I'll post my results.
Next step will be to swap for a spare fuel rail and injectors (only because it's more work. Otherwise I would go in reverse order)

I also meant to ask you if you're getting any knock at WOT, moreso than before?
The trims are ignored during WOT, so if there is a real lean condition to put the trims that high I would expect there to be a fair bit of knock as well.

Sorry Rob, we posted about the same time. Thanks for getting things back on track.

Yes the O2 is cycling. I don't know how old it is but it is an OEM style (not universal).
I was also doing some more reading last night and noticed that my vacuum reading is quite low, 16 in Hg when warm. I'm going to try to eliminate some excess vacuum line (ie emissions) to see if I can get closer to 20 in Hg. There must be a leak hidden in there somewhere I havn't found yet.
If I have enough time tonight, I'll also pull the plugs as well.
I'll put the ECU swap out until tomorrow night.

I don't seem to be getting any counts of knock at WOT. A bit of phantom (I'm hoping) at 10-20% throttle but a quick let off and right back on and it's gone.
Would that indicate a possible faulty MAF or ECU issue?

Jamie, I was watching your tailpipe when you were accelerating from the start and you weren't belching out smoke. It was clean in fact, except momentarily after shift.

Have you checked the plugs?

That's good news. I know my old 7 bolt used to belch lot's of black smoke when taking off.
I disconnected the four lines from the top of the throttle body, then used short pieces just to tie them back into each other (instead of caps) and did the same on the EGR valve. I think that should isolate the vacuum lines to just the FPR/solenoid, BOV, gauge, MBC and wastegate actuator. If I still have low vacuum, it should also make easier to find the leak.
Also, I disconnected the battery to reset the trims. That should give me a fresh start with the new vacuum line setup.

Plug check will have to be tomorrow night.

If you don't supply the "top" side of the EGR valve with boost pressure, it can blow open under boost.

Ok not much change in the vacuum reading.
Trims had drifted pretty much back to 140% by the time I got home after work, probably 60 min total driving of mixed 401, hwy and city.
Pulled the plugs and although consistent, they all were lighter than I think they should be. I tried to get some pictures if anyone can give me some feedback that has some more experience at reading plugs than I do.
<a href="http://s306.photobucket.com/albums/nn251/jvalcamp/?action=view&current=Plug1.jpg" target="_blank"><img src="http://i306.photobucket.com/albums/nn251/jvalcamp/Plug1.jpg" border="0" alt="#1 Cylinder"></a>
<a href="http://s306.photobucket.com/albums/nn251/jvalcamp/?action=view&current=Plug2.jpg" target="_blank"><img src="http://i306.photobucket.com/albums/nn251/jvalcamp/Plug2.jpg" border="0" alt="#2 cylinder"></a>

<a href="http://s306.photobucket.com/albums/nn251/jvalcamp/?action=view&current=Plug3.jpg" target="_blank"><img src="http://i306.photobucket.com/albums/nn251/jvalcamp/Plug3.jpg" border="0" alt="#3 cylinder"></a>

<a href="http://s306.photobucket.com/albums/nn251/jvalcamp/?action=view&current=Plug4.jpg" target="_blank"><img src="http://i306.photobucket.com/albums/nn251/jvalcamp/Plug4.jpg" border="0" alt="#4 cylinder"></a>

I think with the colour of the plugs I'll be staying off the boost until I understand better what's going on.

I also swapped ECU's tonight to see if that makes any difference.

OK, so I haven't fugured out how to embed pictures in my post yet so here are the links:
http://i306.photobucket.com/albums/nn251/jvalcamp/Plug1.jpg
http://i306.photobucket.com/albums/nn251/jvalcamp/Plug2.jpg
http://i306.photobucket.com/albums/nn251/jvalcamp/Plug3.jpg
http://i306.photobucket.com/albums/nn251/jvalcamp/Plug4.jpg

Sorry for the multiple posts but got the picture thing figured out:
#1 Cylinder

#2 Cylinder

#3 Cylinder

#4 Cylinder

One other question, Rob, you mention that trims are ignored under WOT. Is this true whenever the ECU is in open loop mode or just WOT?

The ECU goes into open loop based on several different things, the major player is Throttle position.

All the time you are in open loop, the trims are ignored.
WOT is always open loop.

There's a lot of carbon near the threads, and although the tips look white that could be from a lean idle just before shutting it down.

And no knock...

What's your coolant temperature? If that sensor isn't working, you could have some issues with fueling and probably timing too.

It would be interesting to compare your airflow Hz at a given rpm & boost against another stock setup.
If yours is high it could indicate that you still have a boost leak, or that the MAFS is faulty.

Another thing to check is the compressor inlet pipe.
A leak between the MAFS and the turbo would have you lean all the time!

My 93 is pretty much stock:
3" turbo back
lower HC removed
stock ECU
boost 12/13

Im seeing a max of 1599hz at WOT

Today my fuel trims where:
L - 122
M - 96.8
H - 81

I have all my stock emissions lines in place.

Jamal, it looks like you might have a boost leak.
Could you post the Hz @ 4000rpm & 4500rpm?

this is from a 3rd gear pull this evening.
RPM 3937
INJD 49
TPS 41
991HZ

4300
76
73
1480

4600
92
99.6(WOT for me)
1599

I don't seem to have any pulls at WOT. But there are some good examples of 114% injector duty.

No luck on the other ECU. All trims drifting back to max again.
Next step is to try another boost leak check. I'd like to test out the stock pipe between MAF and turbo for leaks somehow as well.
I was thinking as well that the PCV valve is quite old. It did just pass etest but if for some reason it was bad, could that cause high trims?

It wouldn't be the PCV. You'd only leak boost, and even then if everything is plumbed properly there would be no change in the A:F just a bunch of crankcase pressure.

It's difficult to draw any conclusions from your logs because your TPS is all over the place.

Are you sure that your IDC formula is correct?

RPM * IPW / 1200

6156 * 17.41 / 1200
= 89.31% not 114%

Jamie, what is your Battery voltage like?

Interesting. Those logs are right from MMCD. I didn't do any calculations on them. Is this a setting or possibly a known issue with MMCD logs? How accurate is that formula. Is it an approximation based on certain assumption?
I did get a better pull tonight on the way home although I didn't seem to have it quite on the floor. I think my floor mat was in the way because I know I had it set when the car went back together this spring.


I'll check voltage later on.

Here's some info on that (MMCd):
http://www.3si.org/forum/f1/whats-up-110-idc-421524/index2.html

I got my formula from here:
http://www.stealth316.com/2-calc-idc.htm

Your log doesn't look so bad...
Good timing, no knock, plenty of fuel (if you can trust the narrowband as far as you can throw it).
The IPW does seem high, but I don't think it's quite as bad as you were thinking.
I'd try another MAFS next, and make sure it's on there good.

Thanks Rob. That definately makes me feel a lot better. I ran some calculations on the entire run from tonight and my peak is 97% at 6313 RPM. Looks tight and probably time for some more fuel.
I'm still going to try and chase down the high trim values though. I'll keep my results posted.

Stock boost, you really shouldn't need to add fuel.
What if your boost gauge isn't correct, and you're actually well above 11psi?
You said you have low vacuum (16 inHG) at idle - is it idling rough? I would expect it to.
Maybe the boost gauge line is pinched or clogged.

Jamie, get rid of the can thats covering your airfilter (thats if you have a K&N filter on your car) Use the clips on the stock pipe to hold down the K&N.

Idle is actually quite smooth. I'll check the gauge and line both for leaks and pinched lines.

Air can is already cut.

Jamie, have you experienced any fuel cut with your setup?

No. Thankfully no fuel cut.

Here's something I haven't come across before. It almost appears that my boost gauge is offset by about 1psi to the plus side. The picture below was taken with the car not running and had been sitting for about 20 minutes so any residual pressures should be gone.
This could explain low vacuum and high IDC for the boost I (thought) I was running. Anyone ever come across this before?
If this is the case, I may now be simply looking at dirty injectors/filter.

That is not uncommon.
Note the box at zero, I don't think even AutoMeter expects their gauge will sit dead on zero

I would test against another gauge with vacuum and boost.
Even some cheap ($5-10) pressure gauge from a hydraulic shop would suffice, at least to confirm the more important boost side.
Your vacuum is probably fine (and gauge reads low), else the car would be idling like crap.

The "box" is there to account for changes in atmospheric pressure as well. Remember, it's gauge pressure we always talk about, not absolute pressure.

I use a digital gauge, and have seen the pressure offset as much as 2 psi from any given day to the next. (Luckily, I can 0 it out rather easily).