VCDS Assistance

1997 TDI Jetta, Engine - 1Z

I thought I knew what I was doing but I clearly messed something up. The car starts, idles and runs fine but mpg went way down after mechanically deleting EGR and trying to do the same via VCDS.

I logged all the way in to Admin, went to Engine/Adaptation...

I was looking at ALH settings for deleting EGR, not AHU/1Z

I need to know the following:

- Factory settings for Channel 2

- Factory settings for Channel 3

- How to code out EGR for 1Z/AHU

I've only found how to do so with ALH. Thanks in advance!

AFAIK you can't 'delete' EGR with VCDS on 1z/AHU however, you can minimize the duty cycle by changing the number from 32768 (default) to 33768.

Some have blocked it off but the ECU is expecting to see a drop in incoming air via the MAF when the EGR is open so there's chance you can get a CEL from this.

Only way I know to delete EGR is to through chip tune by requesting that it be deleted.

I found the logs and thats the change I made to channel 3.

Is channel 3 the correct block to change this value?

Steve Addy said:

AFAIK you can't 'delete' EGR with VCDS on 1z/AHU however, you can minimize the duty cycle by changing the number from 32768 (default) to 33768.

Some have blocked it off but the ECU is expecting to see a drop in incoming air via the MAF when the EGR is open so there's chance you can get a CEL from this.

Only way I know to delete EGR is to through chip tune by requesting that it be deleted.

Click to expand...

[strike]33678, though i think if you enter a too-high number, it stays at 33678.[/strike]
Edit: It is 33768.


This thread discusses solid state relays and resistors and such, to fake the readings back to the ECU: http://forums.tdiclub.com/showthread.php?t=424543

Why would the egr delete have anything much to do with mpg? When I deleted mine I actually didnt see any difference what so ever on the stock engine setup. Never once bothered with vcds with it. It's not going to do anything about that cel. How did you delete it? Block off plate? You sure its sealed?

Because the EGR is still connected electrically to the timing system and will cause running problems if not deleted with a tune.

I reset it back to the setting I found in the log file. With cleaned out manifold I'm getting really good mpg again. Thanks to all that assisted.

turbodieseldyke said:

33678, though i think if you enter a too-high number, it stays at 33678

This thread discusses solid state relays and resistors and such, to fake the readings back to the ECU: http://forums.tdiclub.com/showthread.php?t=424543

Click to expand...

Curious where you found that number, everything I've ever read or seen (via VCDS etc) shows up as 32768 stock setting (even for ALH) and the adjusted value or max effect is at 33768.

Steve

Abacus said:

Because the EGR is still connected electrically to the timing system and will cause running problems if not deleted with a tune.

Click to expand...

yea no, i understand that, i deleted mine, just taped over the CEL for years, never saw a drop in MPG, in fact i saw an increase (back to good numbers) from 43 to 45 mpg instantly (but that was also because i cleaned the intake and head!.
still there should be no drop im MPG by simply installing a block off plate.

OP, you cleaned the intake? did you CLEAN THE HEAD???? if you did not, i encourage you not to drive or run it until you do so. failure to also clean the intake runners on the head can result in a engine that is nothing more than scrap. chunks can fly off now that you have it disturbed and more air flow, these chunks can get stuck up against the head and piston and in the valves, this kills the engines.

Steve Addy said:

Curious where you found that number, everything I've ever read or seen (via VCDS etc) shows up as 32768 stock setting (even for ALH) and the adjusted value or max effect is at 33768.

Click to expand...

Damn. I know I googled it before posting, now can't find it. So I checked the faq printout in my repair manual, and sure enough, it's 33768. I had a recollection of doing the adaptation years ago and thinking "that's a stupid number". 32768 is a common "computer number", so it makes sense that it might be programmed into the ECU. But 33768 might as well be 33678.

I hope i'm not turning into "one of those guys."