PhaseP

Yesterday, I replaced the vacuum hose from intake manifold to FPR and the hose from under the intake manifold to the BPV. The car was running fine yesterday after the replacements. This morning when I started it up, RPM jumped to 3000, after a while went to 1300~1400 but the engine was vibrating like I have never seen before. After starting up a few times, now it hardly starts, I need to give gas and keep it over 1K so that it won't stall. The car has lost its mind.

What puzzles me is, it was fine yesterday, and today it is behaving like this. I had opened the intake hose - manifold connection to be able to access the vacuum hose ends. Could some dirt that entered the system from there have caused it? It is like car can't find the right amount of fuel to supply to keep it stable at idle.
Any ideas? Did I hose the MAF? Crap!..
I re-replaced those two vacuum lines to make sure that it wasn't them, still the same thing.

TANMAN

Run a TBA. Did you disconnect the battery at any point?

RKA

and the symptoms do sound consistent with a car needing a TBA.

PhaseP

You guys are right, it definitely looks like throttle body related. I have some improvement but still need some help from the experienced ones.

Do I need to do TBA on cold or warm car?

Here is just what happened, I just went did a TBA, put the key in to on but don't start. 30secs later some whirling and ticking sounds. Watied 5 minutes, started the car. RPM jumped to 1300, and after some warm up drop down to just below 800. This what it used to do with the exception that it used to stay right at 800RPM. The car was shakier than I am used. So I decided to do another TBA. After that now RPM oscillates between 1500 and 700, almost about to stall at idle. What am I doing wrong? Should I wait the car to completely cool and redo a TBA?

I am in New England, right now it outside air temperature is 47F.

I DO appriciate your help.

PhaseP

Thanks, but couldn't find anything wrong with any of the lines

Quattroleap

Any CEL? Did you try TBA

PhaseP

No CELs. After reading RKA's post I tried TBA, (key in on, wait 5mins). When cold it starts better, more shaky than I am used to. But after it warms up, when I try to drive in the parking lot the RPMs really go down at neutral, it almost always stalls while shifting from 1st to 2nd. I always have to give gas to keep it running. After warm up, at idle, RMP's oscillate between 1000 and 500 or below.

Am I supposed to to TBA cold or warm?

Thanks for any input

RKA

for some reason, performing a TBA with a vag.com seems to be a little more foolproof. If you don't have access to a vag.com, then you'll have to live with the results you're getting. BTW, it seems like the first TBA you performed got everything more or less set up right. Somehow the second one didn't go so well.

PhaseP

Just in case anyone is interested, I had posted about bad idling and stalling problems after I had replaced some vacuum lines weekend. Yesterday I took the car to a local mechanic who specializes on European cars. He said he checked for vacuum leaks and couldn't find any, cleared up lots of codes (I had made a mistake of trying to start up the car with throttle harness disconnected), and the car is running fine now.

Thanks to anyone who replied my earlier post to do a TBA. It appears it needed a real VAG TBA.