kpatz

Keep me posted. Is the MPG you posted actual or trip computer?

I'm averaging around 25 MPG actual mileage (~350 miles between fill-ups) but the trip computer rarely goes over 20, probably because of the lean problem.

I'll check the plugs and injectors this weekend.

kpatz

I looked up P1128 in my Bentley manual and two things it suggests is:

"Check exhaust system for proper seal" (How could an exhaust leak cause a lean condition??)

"Check pressure regulation valve of crankshaft housing ventilation". Ok, there's no page in the Bentley manual on how to check this valve. Suggestions? I've had a small amount of oil blowby around the dipstick and oil cap so I've been wanting to check this anyway. Ideas? Anyone? Bueller?

Mrkrad

i did get nearly 400 miles when 100% freeway 85mph cruising.

mechanic inspected for boost leaks only found a couple of crumbling check valves. i'm gonna go check out napa for some cheap check valves to put in and see whats up.

will try to do some loggin this weekend to compare.

did you mention your idle HG vacuum?

Mrkrad

would give a sensation of being too lean.

exhaust comes out, air goes in, o2 sees wrong mixture (lean) you'd probably smell it though.

kpatz

Change out those check valves and your car will run better.

I don't have a boost gauge, so I can't tell you my idle HG. I sprayed the bleep out of my vacuum lines with carb cleaner but didn't get any idle changes.

I pulled my pancake valve and cleaned it, and took a test drive, and got a mult. lambda of 12.5 this time, a bit lower than before. Either I partially fixed something or I didn't drive long enough.

Tomorrow I'll remove, check, and reinstall the entire TIP and everything attached to it (pancake, N75, etc.) Hopefully that will lick any leaks lurking between the MAF and turbo intake.

kpatz

No exhaust leaks (I would certainly smell, and HEAR any such thing). I also ran the O2 tests in the Bentley manual and logged block 031 and the readings looked good. The problem lies either in fuel delivery or between MAF and turbo.