ok! i'll be back.. tomorrow. thanks.

 

Still haven't cleaned out the TB.. prob won't till monday when the snow goes away.

But I noticed that whenever I reset the codes, the car runs great for about 25-50 miles, then slowly deteriorates. (maybe this is why you told me to reset ECU cincy?)

Why?

 

Erasing the fault codes re-sets the ECM, the fuel trims go to 0% and learning process starts over. Let your car run for a while and report what the fuel trims are in data block 32, and what the O2 sensors are saying (can't remember which data block)

 

I actually cant log block 32 unless I pay 100 bucks for the real program. Should I go ahead and buy it? Seeing the lambda values really seems like it would help.. So I'll probably get it.. unless i can calculate the lamba values from o2 readings instead..

o2 sensors I can read. Here is a pic of o2 sensor levels.


Let me know if you want to see this at idle.

What changes the fuel trims? Is it only the oxygen readings, or is there anything else factored in? If the fuel trims are negative, then the mixture would be leaner, and that could be why my ignition is occurring too early right? (22º BTDC as opposed to 12º BTDC)

I cleaned out my TB, but have to get a new gasket for it before I can put it back on.

Right now I think it's either bad MAF or bad vac. leak that's letting unmetered air into the system, causing the fuel trims to go bad which then causes misfires..?
I sprayed ether all over and couldn't find a vac leak, but I'm thinking about going to a shop that has a smoke machine.

Thanks again!

 

refridgerated easiest mod ever 40$ 2 parts and about 20 minutes of time
http://www.audiworld.com/tech/int48.shml

 

Hey, after cleaning out my TB my ignition and throttle angles are normal! thanks!

I also just tested my MAF by driving it to redline, and the max air flow was about 150 kg/s. That equates to about 190 hp. I thought I was making at least 210 hp.. But I guess these numbers aren't too far off to suggest a bad MAF.

If my MAF is fine, what else could be throwing off the fuel trims? vacuum leak?

Thanks for the help.

I'm gonna have to check out that refridgerated glove box mod too!

 

Ok if the cleaning of the TB fixed most of your problems, the cause of the residual negative fuel trim is probably caused by a small vaccum leak.

 

hooray for progress

 

WOW dude, props to you for keeping calm this whole time! I would have been freaking out by now. LOL

Josh

Oh and +1 for a small vac leak causing your lean condition. I need to get one of these VAG-Com setups... i will need a PC laptop to though. Grr....

Josh

 

I just wanted to recap in case someone searches and finds this thread useful.

The problem at Idle was just that my TB was dirty. To test for dirty/bad TB, check your Ignition angle and Throttle angles at idle. (Thanks auditech79)

The problem under boost actually turned out to be my coilpacks.

Moral of the story: Even if your coilpacks are relatively new, they can still go bad.

Btw, I love my car now that it runs right.