N249 Delete completed (edit: see other post)

Mike2kS4 · 07-19-2004, 01:55 PM

I decided to do a more conventional approach, since at least one other got CEL with this. The URL should show you what I did since. I recommend the other method as of now, since it works for everyone and is simpler.

Well, after fiddling a bit with doing a partial bypass of the N249 I decided on just bypassing the sucka altogether. Why? I was missing quite a bit of smoothness in throttle transitions.

It was relatively simple. There are three hoses which connect the N249 and and its one way valve to between engine vacuum, the vacuum reservoir and the BPV's. I unhooked the hose going to the BPV hardpipe, the other going to the back of the manifold and the third, to the vacuum reservoir. In order to remove the last hose, I had to flip over the coolant reservoir. This plastic hard pipe was plugged after I removed the hose (no need to though).

I then reused the almost perfectly bent hose from the vacuum reservoir to connect the hard pipe to the manifold. I taped the end of the N249 connector and dropped it in the valley of the block.

It works better than I could have expected. The BPV's respond infinitely quicker. Very smoooth throttle transitions. I still have to check for a code due to my D/Cing the valve entirely, but I doubt it really matters anyhow.

EDIT: I VAG'd and got an N249 open circuit code. I tried a 5W resistor to no avail. I measured the N249 at about 33 ohms so I'm going to give it a shot with different resistors.

The car works fine with the code, I just want to get rid of it nevertheless.

Overall view of my engine compartment. Don't mind the mess.

You can see the hose routing around to the back of the manifold.

Most of the leftover bits.

This is how it was installed from the factory.

This is how it's installed now, I X'd all the stuff eliminated. The yellow line represents the hose which is the only thing left of the system. The line across the vacuum canister indicates a cap.

http://forums.audiworld.com/s4/msgs/1710479.phtml

***O.W. Kenobi*** · 07-19-2004, 02:00 PM

~~Mike@VAST~~ · 07-19-2004, 02:06 PM

you can go a tiny bit higher if one is available....same applies to the n75 delete.

Mike2kS4 · 07-19-2004, 02:07 PM

In case you don't:

It's a valve which the ECU uses to open and close the BPV's at will. It has its own vacuum storage and can/will dump vacuum to open the BPV's.

Problem is the BPV's aren't directly connected to engine vacuum so their response is delayed by the N249.

Oh, and STFA should reveal quite a bit there, Jedi Master

Mike2kS4 · 07-19-2004, 02:08 PM

~~Mike@VAST~~ · 07-19-2004, 02:10 PM

put that check valve back in and send it to the vac reservoir.

sorry mike, didn't work man. i need that vac cannister.

Mike

~~Mike@VAST~~ · 07-19-2004, 02:11 PM

radio shack, home depot, etc. ;p

Mike2kS4 · 07-19-2004, 02:14 PM

What else does it do?

~~Mike@VAST~~ · 07-19-2004, 02:16 PM

i know when my check valve broke and it lost vacuum, my CEL went on because of that.

if you get past it, great, one less problem to worry about

Mike2kS4 · 07-19-2004, 02:18 PM

Everything is corked anyhow. I'll VAG and report what I find.

07-19-2004, 01:55 PM	#1
Mike2kS4 AudiWorld Super User Garage is empty, add now Join Date: Jun 2002 Posts: 12,096	N249 Delete completed (edit: see other post) I decided to do a more conventional approach, since at least one other got CEL with this. The URL should show you what I did since. I recommend the other method as of now, since it works for everyone and is simpler. Well, after fiddling a bit with doing a partial bypass of the N249 I decided on just bypassing the sucka altogether. Why? I was missing quite a bit of smoothness in throttle transitions. It was relatively simple. There are three hoses which connect the N249 and and its one way valve to between engine vacuum, the vacuum reservoir and the BPV's. I unhooked the hose going to the BPV hardpipe, the other going to the back of the manifold and the third, to the vacuum reservoir. In order to remove the last hose, I had to flip over the coolant reservoir. This plastic hard pipe was plugged after I removed the hose (no need to though). I then reused the almost perfectly bent hose from the vacuum reservoir to connect the hard pipe to the manifold. I taped the end of the N249 connector and dropped it in the valley of the block. It works better than I could have expected. The BPV's respond infinitely quicker. Very smoooth throttle transitions. I still have to check for a code due to my D/Cing the valve entirely, but I doubt it really matters anyhow. EDIT: I VAG'd and got an N249 open circuit code. I tried a 5W resistor to no avail. I measured the N249 at about 33 ohms so I'm going to give it a shot with different resistors. The car works fine with the code, I just want to get rid of it nevertheless. Overall view of my engine compartment. Don't mind the mess. You can see the hose routing around to the back of the manifold. Most of the leftover bits. This is how it was installed from the factory. This is how it's installed now, I X'd all the stuff eliminated. The yellow line represents the hose which is the only thing left of the system. The line across the vacuum canister indicates a cap. http://forums.audiworld.com/s4/msgs/1710479.phtml __________________ 2002 S4 Avant, 6spd. Bone stock. <a href="http://www.autospeed.us"> </a> Caveat: Any advice I express regarding potential tuning and such is purely informational. If your knowledge and abilities are not up to the task, no amount of advice can assist.

07-19-2004, 02:00 PM	#2
*O.W. Kenobi* Rest In Peace Garage is empty, add now Join Date: May 2001 Posts: 19,412	Wish I knew what an N249 was... confused __________________ ======================================== My track videos * Brake FAQ * Kenobi lock pump * Kenobi hazard relay * Lidatek install * 43k oil analysis * 51k oil analysis * 60k oil analysis * 68k oil analysis * 76k oil analysis

07-19-2004, 02:06 PM	#3
~~Mike@VAST~~ Banned Garage is empty, add now Join Date: Jul 2001 Posts: 19,474	nice work mike. i put a 30 ohm power resistor in there in place of the valve....5 Watts will do, but you can go a tiny bit higher if one is available....same applies to the n75 delete.

07-19-2004, 02:07 PM	#4
Mike2kS4 AudiWorld Super User Garage is empty, add now Join Date: Jun 2002 Posts: 12,096	Surely, you Jest. In case you don't: It's a valve which the ECU uses to open and close the BPV's at will. It has its own vacuum storage and can/will dump vacuum to open the BPV's. Problem is the BPV's aren't directly connected to engine vacuum so their response is delayed by the N249. Oh, and STFA should reveal quite a bit there, Jedi Master __________________ 2002 S4 Avant, 6spd. Bone stock. <a href="http://www.autospeed.us"> </a> Caveat: Any advice I express regarding potential tuning and such is purely informational. If your knowledge and abilities are not up to the task, no amount of advice can assist.

07-19-2004, 02:08 PM	#5
Mike2kS4 AudiWorld Super User Garage is empty, add now Join Date: Jun 2002 Posts: 12,096	Thanks, Will do, I'm headed to Radio Shack tonight anyhow ;) __________________ 2002 S4 Avant, 6spd. Bone stock. <a href="http://www.autospeed.us"> </a> Caveat: Any advice I express regarding potential tuning and such is purely informational. If your knowledge and abilities are not up to the task, no amount of advice can assist.

07-19-2004, 02:10 PM	#6
~~Mike@VAST~~ Banned Garage is empty, add now Join Date: Jul 2001 Posts: 19,474	EDIT AGAIN: on my 2001.5.... I set an evap code/CEL. put that check valve back in and send it to the vac reservoir. sorry mike, didn't work man. i need that vac cannister. Mike

07-19-2004, 02:11 PM	#7
~~Mike@VAST~~ Banned Garage is empty, add now Join Date: Jul 2001 Posts: 19,474	12 second s4 sponsored by: radio shack, home depot, etc. ;p

07-19-2004, 02:14 PM	#8
Mike2kS4 AudiWorld Super User Garage is empty, add now Join Date: Jun 2002 Posts: 12,096	From the 2.7T guide I was lead to believe that reservoir was for the N249 only. What else does it do? __________________ 2002 S4 Avant, 6spd. Bone stock. <a href="http://www.autospeed.us"> </a> Caveat: Any advice I express regarding potential tuning and such is purely informational. If your knowledge and abilities are not up to the task, no amount of advice can assist.

07-19-2004, 02:16 PM	#9
~~Mike@VAST~~ Banned Garage is empty, add now Join Date: Jul 2001 Posts: 19,474	i think it's vacuum for some evap purge valve. i dunno. i haven't looked much into it..but, i know when my check valve broke and it lost vacuum, my CEL went on because of that. if you get past it, great, one less problem to worry about

07-19-2004, 02:18 PM	#10
Mike2kS4 AudiWorld Super User Garage is empty, add now Join Date: Jun 2002 Posts: 12,096	*It held a tiny* bit of vacuum when I unhooked it, doubt it has another function.** Everything is corked anyhow. I'll VAG and report what I find. __________________ 2002 S4 Avant, 6spd. Bone stock. <a href="http://www.autospeed.us"> </a> Caveat: Any advice I express regarding potential tuning and such is purely informational. If your knowledge and abilities are not up to the task, no amount of advice can assist.

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