Mrkrad

but i was under the assumption that without hardcore timing tweakage (and APR is known to throw more timing than boost at the power) you should multiply the g/s * 1.25 = bhp (assuming sea level)

the 150hp old school b5's ran 120g/s = 150bhp
really unless they are throwing insane amounts of timing at the motor i can't imagine why this would be too far off.

Now you might say no boost leak, but if you did have a boost leak, that turbo might be pushing 25% harder to meet requested boost. and by pushing that hard there would be extra heat (and less dense air flow).

I've got a tiptronic and my chip seems to request more boost. heck even the old nuespeed 91 octane generic chip requested 2300mbar always and delivered it.

seems kinda low that maf reading?? you live in the desert?

p.s. almost all the vw folks i questioned said 180-190g/s chipped k03s i know our cars are different but thats what they are moving.

kpatz

I "only" got 2300 requested and actual on my 3rd gear run before I had to lift off the gas due to traffic. Opportunities to accelerate from 30 mph to 90 mph uninterrupted WOT are extremely hard to come by in these parts. I only got to around 5K RPM on that pull. I probably would have topped 2500 if I could have kept going.

I live in the northeast. No desert here.

Besides, my problem isn't with boost, it's with running too lean.

One possibility I thought of though, that might fit the boost leak theory, say I had a leak after the turbo that wasn't big enough to affect boost levels, but in part-throttle cruising scenarios (most of my commute drive) where no boost is requested, the leak allows unmetered air in, leaning things out. Plausible?

Mrkrad

the k03 can't hold 2500mbar for more than coupla thousand rpm long.

only asking for 1800mbar thats damn near stock boost man.

you don't need to speed to see peak boost. it occurrs about 3200rpm or so (depends on mods/tip/manual/etc)

boost tapers off to stock levels when the peak whp is realized very low in the rpm band.

you would probably move maximum g/s way before redline mang.

kpatz

Still seeing multiplicative lamba corrections in the 14-16 range, but haven't seen it go higher since I did the WOT runs yesterday.

I put a bottle of Techron in the tank and got a can of CRC MAF cleaner, so I'll try cleaning the MAF sometime and see if that makes any difference.

If that doesn't help, I'll figure out a way to check the injectors. Maybe one is faulty. I may pull the fuel rail and put the injectors into plastic cups and have someone crank the car so I can compare the flow rates of the injectors. Sound like a plan?

Mrkrad

thats the old school way of testing.

All it takes is one screwed injector to lean out and mess up the air fuel readings of the others.

one would think this motor supports cylinder selective correction factors, but that would assume detonation or misfire.

I'd be more interested in seeing fuel pressure somehow. i was meaning to log but my laptop battery was dead.

injectors squirt alot of high pressure fuel, so i strongly suggest you be careful and wear goggles. if you want to test them almost every shop has a injector flow bench. take them off, they run them at XX% duty cycle for XX seconds then measure the beaker/test tube for XX milliters. They can usually clean them too. but i've seen many an injector fail/clog in attempts to clean them. i would just replace a bad injector (set). its costly but so is a piston through the side of the block.

i'd do something like:
1. all 4 plugs black/carbon = bad maf/bad o2/vac
2. one plug ashy/white of set = bad injector
3. one plug blacker/carbon++ = bad coilpack/sparks
4. light crustaceans on plugs = water, bad.
5. oil on plugs = oil , bad.

CHECK THE RAIL WIRING! make sure the fuel injector wires are not touching the valve cover it will melt the wires (together/short to ground).

kpatz

I'll check the plugs this weekend as you suggested. I also got a can of CRC MAF cleaner and a bottle of Techron. The Techron is in now. Lambda hit 21% coming home from work, but no codes thrown, yet. Maybe it didn't stay that high long enough. I switched to my APR stock file and will log tomorrow's commute to see if that makes a difference.

I checked the injector wiring this morning. Although it's touching the valve cover a little, it isn't melted (it seems well insulated). I wiggled them to be sure. Besides, wiring problems (open or short) would throw a code.

I also checked the vac lines in the top of the engine compartment, and they're all fine. I haven't checked underneath yet, but the symptoms don't seem to point to a leak anyway.

kpatz

Here's some more points to ponder:

1. In chipped mode on a normal highway cruise, my mult. lambda correction is usually 15-19%. In stock mode, it's higher (~21%).

2. When I do a WOT run, the correction goes down to ~12-13% for a bit. Seems like the car is "happier" when a lot of air is pushed through the engine (heck, I'm happier too! Danged traffic and speed limits...).

3. The value seems to be higher when it's colder out, and lower when it's warmer. This likely corresponds with the air density.

4. My idle is a bit rough when it's warm outside, but it's smooth in colder temps.

I ran a couple more logs, one in stock mode this morning and one chipped during lunch. Both included a WOT run in 3rd gear. On the stock run, my highest MAF reading was 131.39, at 5100 RPM (didn't make it to redline due to traffic). On the chipped run, my highest reading was 160.92, at 6120 RPM (once again, hit traffic).

Thoughts? Help me Obi-wan Kenobi...

EDIT: Fat-fingered digits on chipped MAF reading... oops...

kpatz

Here's my logs from today:

This morning, in stock mode: http://www.patzcatz.com/audi/log-01-001-002-032-Stock.csv
Lunch time, in chipped mode, 3rd gear WOT run: http://www.patzcatz.com/audi/log-01-002-002-032.csv

kpatz

I pulled the MAF last night and sprayed it down with CRC MAF cleaner spray. I also noticed the hose clamp holding the TIP to the MAF wasn't tightened down, so I made sure to do so when I reinstalled the MAF. I thought maybe that was the problem, but no dice. Same result this morning, lambda correction around 17%.

I guess I'll be pulling/checking the injectors this weekend. I'm beginning to wonder if it's the fuel pump. It's not the filter since I replaced that just a few months ago.

Mrkrad

The vibrant are getting black on my car dunno if thats just lack of washing it. lol. but seriously lame gas mileage i am getting. it is in the shop today to once-over. I'll let you know what i find.