TDI Timing Revisited

[UhOh]

Ok...I'll have to take a look at mine tonight, but I've never seen that late/early business. Somebody else with more experience than me can chime in here...but I've only ever seen the timing numbers (in degrees or the range of numbers that the ECU uses).

Well, I might now have more experience! Same equipment, similar car, same procedure and it's what I'm seeing: don't see it on my car.

Was her car idling during this time, and was it up to operating temp? Requesting 4-7.5 degrees ignition advance is weird if so...

Yes. Yes. Yes

I'm not sure why VW called the SOI valve the "Cold Start Injector"...that's not really correct imho. Some call it the commencement valve as well...but I've gotten used to SOI valve. In any case, the Cold Start Injector seems like a mis-label.

I am kind of side-stepping the entire notion of trying to make sense of the Cold Start Injector for now and just going along with it. Yeah, it's kind of confusing: in my head I just refer to it as "that other element/function being measured."

According to the log data you posted for your car, your mechanical timing is slightly advanced. The ECU is requesting 0.4 degrees BTDC, and your actual is at 1.8 degrees BTDC, and the SOI valve duty cycle is at 2.8 (this is max retard). So, the ECU is requesting slightly more ignition retard than the SOI valve is capable of. You'd have to retard the pump timing slightly if you want actual to meet specified..

OK, thanks for confirming. Seeing as this is at idle I'm figuring that it's not all that problematic.

One other interesting point that I was trying to hold off mentioning, until I could understand whether it was something I was doing wrong or not, is that in my car I'm able to maintain Group 004 while manipulating the throttle (increasing/decreasing RPM): and it gets logged. In my wife's car VCDS seemed to just get stupid each time: it's the wireless Beta version, so perhaps I've encountered something that's snagging on a bug.

 

[Rembrant]

OK, thanks for confirming. Seeing as this is at idle I'm figuring that it's not all that problematic.

Well, it's not just at idle...it's anytime your ECU is requesting ignition retard beyond 1.8 BTDC. Your car may only request 0.0 or 0.5 degrees while cruising at low load...lets say 55 mph in 5th on flat ground.

Not that it's a problem or anything...the general consensus is that a little more ignition advance is 'better' anyway...and there are all kinds of people out there with their timing advanced way further than yours.

There could very well be bugs with the beta VCDS wireless version. I know it exists, but know nothing else about it. I drag the laptop out to the car with me...it help my little peach pit brain grasp the data that's in front of me better...lol.

Might wanna look into the wife's car though and see if you can sort it out. With two cars that are the same, you should be able to compare them back to back and see similar numbers.

If the SOI is acting flakey...there are several different things that can cause it to do so.

Cheers,
Rem

 

[UhOh]

Must have not been in the proper place when fetching data for my car!

I went Engine->Basic Settings->Group 004 and got pretty much the same results as with my wife's car. Requested SOI seems to cycle between "Late" with an Actual SOI of 1.5 and CSI (Cold Start Injector) of 2.8 to an Requested SOI of "Early" with an Actual SOI of 8.1 and CSI of 63.

 

[Rembrant]

Must have not been in the proper place when fetching data for my car!

I went Engine->Basic Settings->Group 004 and got pretty much the same results as with my wife's car. Requested SOI seems to cycle between "Late" with an Actual SOI of 1.5 and CSI (Cold Start Injector) of 2.8 to an Requested SOI of "Early" with an Actual SOI of 8.1 and CSI of 63.

Ahh, interesting stuff!

I was going to start moving my IP timing round to see how things worked, but I just filled up today and managed 54.3 MPG...I think I may just leave it alone...lol...maybe...likely not...lol.

I know any improvements past this will be marginal at best, or require some hypermiling that I'm not sure I'm dedicated enough to do...but my timing 'feels' like it's pretty good. Still, I'd like to run a tank or two with my artificial advance removed to see if the car will behave just as well with absolute stock specs.

I guess we'll see. Never a dull moment when you're fascinated with the fuel gauge...lol.

Rem

 

[Rembrant]

Must have not been in the proper place when fetching data for my car!

I went Engine->Basic Settings->Group 004 and got pretty much the same results as with my wife's car. Requested SOI seems to cycle between "Late" with an Actual SOI of 1.5 and CSI (Cold Start Injector) of 2.8 to an Requested SOI of "Early" with an Actual SOI of 8.1 and CSI of 63.

Whoa...wait a sec...

Is this at idle?

Timing is swinging from 1.5 to 8.1?

 

[FlyTDI Guy]

He's looking at Group 4 but in basic settings. Not the way to read timing.

 

[UhOh]

He's looking at Group 4 but in basic settings. Not the way to read timing.

Ugh! I went back through this thread and it seems that people were all over the place. It's confusing as heck! Post eleven seems to clarify (emphasis added):

Touche. 004 needs to be viewed in measuring blocks though in order to get meaningful data. Otherwise the ECU just cycles the N108.

 

[RacerTodd]

Timing is not read in Group 004. I believe going to Basic Settings in Group 004 just cycles the N108 valve (that sets SOI) back and forth, hence the early and late indication.

Use Group 000.

Start your engine and make sure the coolant is up to normal running temp.

Start VCDS.
Click [Select]
Click [01-Engine]
Click [Meas. Blocks - 08]
Go to Group 000
Click [Switch to Basic Settings] (engine note may change)
Click [TDI Timing]

Select your engine code from the drop-down menu (ALH >1999)


Group 000 looks like this, Group 004 is also seen here:

Graph will look like this:

This timing is low, but within spec. It's normal to see the timing jump up and down a couple of dots.

 

[FlyTDI Guy]

I might add, dynamic timing is read in Group 4 but not static. It is also read under Measuring Blocks only, not Basic Settings. There is worthwhile data to see in Group 4, especially if you log it. Things like max advance (WOT) and general behavior as you cruise, accelerate, idle, etc. There's also a world to discover by adapting Group 4 up/dn to vary the range dynamic timing effects. It is discouraged by most 'official' sources but many have gone there, including myself. Also, I've taken the liberty of quoting some comments from Ross-Tech regarding basic settings...

Warnings:
• You should refer to the Factory Repair Manual for your particular car (or some other documented procedure) before "playing" with the Basic Settings function. Failure to follow the proper procedures can result in serious damage to the vehicle.
• Although you can use the [Up] and [Dn] buttons to scroll through the available groups just like on the Measuring Blocks screen, this is probably not a good idea since you may put the Controller into Basic Settings for a Group that you did not intend.
You should enter a Group number directly and click [Go!]

[Switch to Meas. Blocks] will switch back to the passive (and "safe") Measuring Blocks mode, in controllers using KW-1281. In Controllers using KWP-2000/CAN/UDS, there may be an [ON/OFF/Next] button that allows you to initiate and exit Basic Settings while still being able to see the values in the measuring groups. This does not appear every time and it's appearance and function are up to each controller in the car.

Notes:
• Multiple Groups are not permitted in Basic Settings. The data presented in each Basic Settings Group varies greatly from Control Module to Control Module and between different models and years. Some groups are documented in the Factory Repair Manuals, but many are not.
• VCDS tries to elaborate on the meaning of the data as much as possible but the "Data Type" information coming from the Control Module is not very precise. For example: VCDS can tell that a particular field contains a Temperature, but the data from the Controller doesn't tell us whether this is the Coolant Temperature or the Intake Air Temperature.
• To reduce the confusion, VCDS supports Label Files and will display the name of the Label File. The Label File name is displayed on the top left when you are in Measuring Blocks or Basic Settings. If you click on the name of the Label File, the file will open in Notepad or whatever program you have set to handle *LBL files. When a Label file for the Control Module you are looking at does not exist, VCDS will come up with an "educated guess" for what a particular Data Type means. The dealers' VAG-1551 and 1552 scan-tools do not provide any elaboration; they only show what’s in the display fields! Basic Setting will display a popup balloon when the mouse if hovered over each value, if the Label File contains information for that field in that controller. See the Measuring Blocks section for more information.

 

[RacerTodd]

I might add, dynamic timing is read in Group 4 but not static. It is also read under Measuring Blocks only, not Basic Settings.

Correct. When I think of "timing" on my car, I think only of static timing. That's usually all I'm concerned with - getting the mechanical pump timing correct.

 

[UhOh]

OK, sorry to bring confusion to this thread.

I've now got proper orientation and have revisited what aNut first posted. I get IT, though am still not sure why others' experience with more advanced timing is working better for them.

Both my cars have a 1 to 1.5 degree advance (noted via Group 004, at idle). Both run really well. Both are getting right around 50mpg (90+% highway driving). Wife's car, however, and this is the reason why I latched on to this thread, has "cold" crank issues, sluggishness; I am now ruling out the problem as being timing related (it COULD have been related, but based on what I'm seeing it's not): I'm going to check out the starter (found a nice post by Todd on doing this- thanks, Todd!). I MAY look to change static timing such that it gets me matching SOIs (Requested and Actual), see if that improves fuel mileage.

For what it's worth (as an attempt to actually contribute to this thread), here's an interesting discussion about affects of fuel on timing, from a biodiesel forum (and mostly folks with Cummins engines, though there's someone with a PD TDI):

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/419605551/m/4887040553/p/1

 

[swetbak]

I just installed injectors with new nozzles (from DBW) and checked my timing according to this thread. Static is right on the "blue" line. Dynamic is reading 4.4 BTDC for both specified and actual. Duty cycle is 60%.
Is my dynamic timing ok since both specified and actual are the same?
If not, how am I supposed to reduce both?
I've never checked these dynamic timing numbers before, so I don't know what they were before the new nozzles.
Thanks

 

[FlyTDI Guy]

A stock ALH (no tuning, no adaptations) usually reads about .4º BTDC @ idle. Is your Group 004 set to 32768 (stock)? Static setting aside, 4.4 BTDC @ idle is somewhat advanced for a fully warmed stock engine. Cold settings (while cold start valve is active), this would be more normal.

 

[swetbak]

If you are asking about my IQ adaptation, yes it's at the default 32768. Engine was very warmed up.
The nozzles are the only mod (1019's), and the PD 150 intake.
Should I be concerned with the advanced dynamic timing?

 

[FlyTDI Guy]

IQ would be Group 001. If you are familiar w/checking your IQ adaptation, try looking at Group 004. See if 4 is also set at 32768 and check back.

 

[Rembrant]

Dynamic is reading 4.4 BTDC for both specified and actual. Duty cycle is 60%.
Is my dynamic timing ok since both specified and actual are the same?
If not, how am I supposed to reduce both?

Check the timing adaptation as FlyTDI Guy suggests, and see if it's stock.

To get the duty cycle down, you have to adjust the pump. Go back and read the beginning of this thread...it is explained where to set the timing and where you want your duty cycle to be.

A stock ALH (no tuning, no adaptations) usually reads about .4º BTDC @ idle. Is your Group 004 set to 32768 (stock)? Static setting aside, 4.4 BTDC @ idle is somewhat advanced for a fully warmed stock engine. Cold settings (while cold start valve is active), this would be more normal.

Yup. I have my ALH timing adapted 3+ degrees, and during hot idle, it sits right at 3.5 degrees. Before I adapted it, it was requesting 0.4 BTDC.

 

[swetbak]

I haven't been able to check yet, but to make sure I understand. I use adaptation to move specified and hammer mod to move actual?

 

[Rembrant]

I haven't been able to check yet, but to make sure I understand. I use adaptation to move specified and hammer mod to move actual?

Forget about IQ and the hammer mod for now. This thread is about injection timing. Timing is the "when", and the IQ is the "how much".

Regarding timing:

What the ECU is asking for is the specified.
What the injector pump (SOI valve) is doing is the actual.

To change the specified, you use adaptation.
To change what the injector pump can do, you have to adjust it by rotating the sprocket. (This is where you change the SOI valve physical limits and duty cycle with regards to engine TDC).

 

[swetbak]

Ok, I got it. Thanks Rembrant.

 

[swetbak]

A stock ALH (no tuning, no adaptations) usually reads about .4º BTDC @ idle. Is your Group 004 set to 32768 (stock)? Static setting aside, 4.4 BTDC @ idle is somewhat advanced for a fully warmed stock engine. Cold settings (while cold start valve is active), this would be more normal.

My timing adaptation in Group 004 is 33168.

 

[Rembrant]

My timing adaptation in Group 004 is 33168.

That sounds about right based on what you're seeing. Somebody advanced it in the past. You can drop the number back down to the stock number...hit test, then save...(I think...going by memory here), and that will 'correct' your timing to stock specs....IF you want it at stock specs.

 

[UhOh]

I'm trying to apply this to my cars, so...

Stock Requested SOI is 0.4 degrees, which means that my ECU is set/programmed to the stock value. My Actual SOI, however, is roughly 1.5 to 2.0 degrees, to the plus side, in which case I'm about 1 to 1.5 degrees advanced, correct? My Duty Cycle is at the lower bound of 2.8%, which, I believe, tells me that I cannot lower the Actual to meet the Requested via adaptation [ECU]. Continuing...

If I adjust Requested SOI, via adaptation, up to meet my Actual SOI of about 1.5 to 2.0 would I still expect to see 2.8% for the Duty Cycle idle? (my understanding is that the Duty Cycle is unable to push Actual down to meet Required because it's as low as it can go) Or perhaps more simply phrased: When both Requested and Actual SOIs match at idle the Duty Cycle will/should be 2.8%?

I'm not asking if I SHOULD be running 1 to 1.5 degrees advanced. I'm just trying to apply my understanding of how this all works, given the examples that I have parked outside

 

[Rembrant]

I'm trying to apply this to my cars, so...

Stock Requested SOI is 0.4 degrees, which means that my ECU is set/programmed to the stock value. My Actual SOI, however, is roughly 1.5 to 2.0 degrees, to the plus side, in which case I'm about 1 to 1.5 degrees advanced, correct? My Duty Cycle is at the lower bound of 2.8%, which, I believe, tells me that I cannot lower the Actual to meet the Requested via adaptation [ECU].

Yes, all correct. Your pump mechanical timing is just slightly too advanced...so it is not able to retard to the requested 0.4 BTDC specified.

Yes, if you change the requested timing in adaptation to your actual numbers, then yes, your requested and actual should be the same, and the duty cycle should still be at 2.8%-ish.

Continuing...

If I adjust Requested SOI, via adaptation, up to meet my Actual SOI of about 1.5 to 2.0 would I still expect to see 2.8% for the Duty Cycle idle? (my understanding is that the Duty Cycle is unable to push Actual down to meet Required because it's as low as it can go) Or perhaps more simply phrased: When both Requested and Actual SOIs match at idle the Duty Cycle will/should be 2.8%?

In your current situation, yes.

If you go by the specs from the beginning of this thread, you would adjust the mechanical timing slightly, and not use adaptation at all.

Technically, the SOI valve shouldn't bottom out (@ 2.8% duty cycle) until it hits 2 degrees ATDC. Just for reference is all. I know you were asking about how it works...not where it should be set. I think now...15 years later, the Jury is still out...lol.

Rem

 

[swetbak]

I reset timing adaptation back to 32768.
Now my spec is 0.4 and actual is 0.7-1.1 and duty cycle is 2.8%
My static timing is dead on the blue line at 50. I may advance that a little later, but right now I'll keep things as is.

 

[UhOh]

Well... I decided to just tweak via adaption, figuring that it wouldn't really be much of a change anyway. Bumped up Requested to meet Actual at idle to 1.8 degrees. Duty Cycle shows as 4.8%. The adaption number came out to be 32900.

If I find anything earth shattering here I'll follow up. It's been a great thread!

 

[trj]

Great thread! Having just done my first ALH TB I read this with great interest....and several others too. I find myself wondering if I am going to damage something messing with VCDS in the IQ adaptation and the EGR issue.

I have a couple of questions:

- If you lower the amount of fuel (through IQ adaptation) too much will that lean out the system to the point there may cause damage to the engine? Either way how much is reasonable and how much is too much deviation from factory 32768? I read the specified and actual need to match. Right now my graph shows about 5 dots above the middle (blue) line. Specified is .4 BTDC and actual varies from .4 to .7, some times going up to .9 BTDC. Is this close enough or needs work? (OK that's several questions. Help me out here please?)

-Also.........In this in TDI FAQ: http://www.tdiclub.com/TDIFAQ/TDiFAQ-7.html#j (Item J) "Avoiding the Need for Intake Manifold Cleaning - Recalibrating the EGR System"

The above says to change adaptation value from 32768 to 33768 in block 3 to eliminate problems with EGR/intake system clogging. I hope I am correct that this is different than block 000 where we are changing IQ from the factory setting of 32768? Are these separate independent issues? Factory setting adaptation numbers are the same, is that just coincidence? If you change these are there compounding issues involved?

Another question on this item. If they are separate and you change from 250 mg/stroke to 370 mg/stroke as suggested in block 3, is that going to lean out the fuel/air combustion in the cylinder chamber on injection and be a problem?

I'm new to this so be patient please!

 

[UhOh]

Regarding the EGR adaptation one is free to find out what it does, but, be forewarned:

http://forums.tdiclub.com/showthread.php?t=60469

As long as you have the EGR valve on and functioning (which I tend to promote) you cannot ELIMINATE the issue, only mitigate it. I've faced TWO cleanings, one requiring cleaning of ports on the head; I kept my EGR components. Only tunes, which account for this alteration throughout their maps, can properly alter the EGR functioning (with expected results).

The thread should get back on track about fueling issues, about hammer-mods (which I defer to the more experienced to comment on).

 

[Rembrant]

I have a couple of questions:

- If you lower the amount of fuel (through IQ adaptation) too much will that lean out the system to the point there may cause damage to the engine? Either way how much is reasonable and how much is too much deviation from factory 32768? I read the specified and actual need to match. Right now my graph shows about 5 dots above the middle (blue) line. Specified is .4 BTDC and actual varies from .4 to .7, some times going up to .9 BTDC. Is this close enough or needs work? (OK that's several questions. Help me out here please?)

I think you're getting IQ and Timing mixed together here.

The IQ is how much fuel gets injected.
The Timing is when the fuel gets injected.

If you've just done a timing belt job, you want to focus on timing, and forget about IQ for a moment.

 

[trj]

UhOh

Interesting thread, think I'll leave my EGR alone.

Rembrant

As best I understand it the OP says to keep setting the initial timing higher until you aren't getting initial and actual to match, then go back where they are matching. Where did I make a wrong turn?

 

[UhOh]

UhOh

Interesting thread, think I'll leave my EGR alone.

LOL! Yeah, pretty hard to dispute after reading it. For me I'd already "tested" what so many others were promoting. Sometimes people over-react to things and don't really stop and analyse based on facts and logic. This is one of those cases.

While this is a bit of a side-track to the thread I believe that it serves to support what the thread is about, and that's that there's static/physical settings and then there's dynamic, ECS settings/control. One ought to understand how each behaves in order to get expected results.