bogging problem, please help

[preston90tsi]

hello, thanks for checking out my thread. so im having a problem with my 90 tsi AWD that i picked up a few weeks ago. im not even sure what all is done to this thing. but when i drop RPMs fast, it will bog really low, depending on how high the RPMs were. and in alot of cases it even dies. it seems to have gotten worse the past few days. any suggestions on what i should check out? ive been told maybe my timing is off? or possibly a vacuum leak. i checked for any obvious leaks but have found none. any input would be great.

 

[Mizzat508]

I've got a 2g FWD, but it sounds similar. Whenever i put it in neutral to stop or something, it'll bog to 500rpms or less and then go back up to 1k. I have a feeling this is due to the fact I have a CEL for a p0170 Fuel Trim Malfunction, so this may or may not be the same problem your having.

 

[blkgst97]

Have you done a boost leak test? and is your bov recirculated?

 

[preston90tsi]

yes my BOV is recirculated. and no i have not done any boost leak tests. how would i go about that?

 

[95'RS-T]

Visual Frequently Answered Questions - Home Page
Click on intake and scroll down till you see intake leak tester.

 

[Mizzat508]

Stock bov, and its recirculated. Haven't done a boost leak check, the guy who sold it to me said he did...i'll pick up some pvc and a coupler to test it this weekend.

Also, the previous owner cut the side of the air box out. It still sucks air through the filter, but could that be causing the bogging issue?

 

[BLINKY619]

iacv