I have a 99 a4 1.8t quattro automatic. Just replaced crank breather and a couple other pcv lines. Put all back together. Now when maf is plugged in car starts and dies instantly. When unplugged it stays running but stalls our tries to stall when put into gear or when coming to a stop.and insight much appreciated message me here our text me at 605 951 5512. Thank you for your time

 

Sounds like you have a reasonably large vacuum leak. You'll need to perform a visual check for damaged vacuum lines and check valves. Performing a boost leak test could also help pinpoint the leak.

 

I have visually circles everything I could think of.I can hears his but no clue where its coming from. I just replaced crank breather old one was broken into a million pieces car would barely run I thought it was maf when unplugged ran great.when plugged in it stalled out all the time. Maf was checked with vag and said to be good. My mechanic said with the broken crank breather the ecu was getting bad info.with maf plugged in.. When unplugged it want getting any info so it ran better. Now that the crank breather is replaces suction jet pump replaced the line coming from suction jet to intake manifold replaced and line from bleeder valve to suction jet replaced. Still dies with maf plugged in and runs, although very slow, with maf unplugged. Not sure how to do boost leak check.

 

Heres a link to that diagram
VWVortex.com - Pancake valve / 034 valve / hockey puck / crank breather valve HELP!!?!?!?!

 

Anyone else? Please help... I believed have a bad pancake valve...as far as I can tell there is no diaphragm in it. What kind of problems would that derive...?

 

To do a boost test good the tennis ball method for b5s, just remember not to add to much pressure or you will have even more leaks. You said you have vag-com, did you scan all modules for codes and are there any?

 

I personally don't have vag my mechanic in Sioux falls does. I am the hours away with a broken car lol. What exactly is tennis ball method? Anne good write UPS?

 

https://www.audiforums.com/forum/aud...-tester-37596/
Do you have any scan tool?

 

I have a standard elm obd scan tool that runs through my phone

 

Okk so update everybody. Thanks for help so far. Did the leak test figured out had a bad check vaslve. Replaced it, the crank breather also want seated properly, fixed it also. Car now holds a constant 10 psi of pressure when tested. Car starts doesn't want to stay running of I pump the gas it will idle up as high as I want (with lots of hesitation and stuttering) then idles back down and dies now I'm noticing that when I do get it to idle up I have blue smoke coming from exhaust pipe. I'm so lost don't know what to look at next. Please help. Text 605 951 5512 to reach me please and thank you