TDI Timing Revisited

[Matt-98AHU]

Last night I was trying to adjust my specified vs. actual timing by adaptation in block #4 but it doesn't exist ( original black BK ECU).

I think to bring actual vs. specified I will have to manually adjust IP in basic settings - retard timing from 55* to mid-line /blue/.

Right now I have:

Engine speed / Specified start / Actual start / Cold start valve

-----882 -------0.4*BTDC-------1.4BTDC -------3.1%

One more thing, when I switch from measure to basic setting in block #4
my Specified go to 8*BTDC and Actual follow to 8*BTDC too

Engine sound change too, any explanation why this is happening?


Tom

Probably shouldn't switch to basic settings in measuring block 4. That will probably cycle the timing advance solenoid, or at least tell it to goto a different advance than is normal.

You're supposed to goto measuring block 000, THEN basic settings to figure out what the pump timing is. Use the TDI timing graph to plot the fuel temp and timing on the appropriate graph selected from the drop down menu.

 

[Biczek]

Yes , I know Matt, but I was trying to bump my Specified Timing at least 0.6* to match Actual Timing and see what will happen.

My timing is 1/3 above blue line 55*.

Look like ours black BK ECU don't support that function.

On the side note I did quick runs with logs but now I have to figure out how to transfer data from my notebook.

IIRC my logs , Actual Timing was right along Specified on 3rd gear(all the way to 4,000rpm), on 1st and 2nd was slacking.

Maybe just set timing in basic all the way to green line and leave there?


Like DBW said:
"Static timing ABSOLUTELY affects timing but not the way you think.

Don't confuse dynamic (ECU controlled) with the Static timing. One controls the start of injection (SOI) the other (static) controls the curve of the pressure wave after SOI increasing the rate of delivery (thus advancing the timing after SOI begins) and has a significant affect regardless of what the ECU is doing.

Static timing using a PowerPlus 520 and stock ECU plotted the following on the Dyno and in actual driving conditions:
Top of the range = +5hp and +2/3 mpg (higher top end torque)
Middle of the range = +/- 0 Neutral torque bias (as published)
Bottom of the range = -10 hp -2/3 mpg (increased low end torque but rapid loss at high rpms).

To sum this up:
Static controls the pressure rise after SOI
Dynamic controls the SOI "

 

[TdiScottie]

I just performed this procedure on my 2003 Jetta TDI yesterday. I had checked my timing about a month ago, and it was just below the top line. When I checked yesterday, it was now a hair above the top line, and vagcom said it was out of spec. I've owned the car for about 5k miles, and I don't know if it was deliberately advanced or if the dealer just left it that way on their TB job. I regularly run a B20 blend, and may try full bio this summer.

A few notes on the procedure:

The three 13mm bolts on the IP were blue on my car. I do not know if they were stretch bolts or not. I replaced them with new bolts ordered from idparts. The new bolts are not blue. They are the normal brownish gold color that a lot of bolts are.

I was initially confused as to which way advances and which way retards. For the record, clockwise advances, counterclockwise retards. I started going clockwise thinking that would retard the timing, and then my timing was way off the chart advanced. I tried counterclockwise and that brought me back to spec.

This really is an extremely fine adjustment. A tiny movement is significant on the timing graph.

I did the ritual of "check, turn off car, loosen, move sprocket, tighten, start car, check again" about ten times before I got it close enough to my liking.

In the end, it was slightly retarded, and the specified vs actual matched.

Driving impressions:

I think it's a little bit less powerful, but not much.

There used to be a 'nailing' sound at idle that was quite pronounced. It is much quieter now.

The engine seems smoother. Steady state cruising feels better, like the car is happier cruising along.

This AM, it was around 40 degrees. Starting took a revolution or two more than it normally does. I did not see any smoke on startup.

I will post mileage after a few tanks. I typically got 46-48 before the procedure.

 

[Biczek]

Injection pump timing

Need some thoughts, I did some sprint runs logs on 3-rd gear from 1500 to 4500 rpms.

What do You guys think of my Actual timing, is it normal to react so slow from 1500 to around 2000 rpms ?











Tom

 

[lirunaway]

I have the latest version of vcds. I could not get these readings under "basic settings". I get an error. I was able to somewhat see it under "readings". The graph kept all the lines along the bottom so close it was too hard to tell anything. Idle running 4'BTDC. I changed the timing belt. Now it's running 6' BTDC. Any thoughts welcome.

 

[whitedog]

You have a different engine than the one being discussed. You need THIS thread.

 

[lirunaway]

You have a different engine than the one being discussed. You need THIS thread.

Thank you,
This keeps happening. I really wish they would separate these groups by engine.

 

[whitedog]

Thank you,
This keeps happening. I really wish they would separate these groups by engine.

Yep. been there, done that. Separating the engines has been discussed and it won't happen since they are too entwined.

 

[tdiben]

My verdict on an AGR engine

Hi there,

I've been reading all these threads about pump timing for a few months now and finally yesterday got round to doing some adjustments. I'm from the UK and have a 1998 Mk4 Golf with an AGR engine (Same as ALH except has a KKK wastegate turbo). Ever since we've owned the car we've had 2 main issues with it. The slow down shudder, which has been really bad, and it's taken an excessive cranking to start when hot but starts in a split second when cold. From what I've read these problems are really really common. I checked the pump timing using VCDS and found it to be too advanced (this was after a cambelt change and having everything locked in place correctly with pins). The graph showed it to be out of spec above the green line. The performance of the car has been very very good though. We've had 2 of these AGR engined Golfs now and this one is definitely the most torquey of the 2 and easiest to drive. I had always assumed this was due to the pump timing so have always been reluctant to change it until now.

Yesterday, however, I decided it was time to adjust the pump timing. I followed the procedure provided on here for the ALH engine and now have it set exactly as described at the beginning of this thread. The graph now shows the timing to be a fraction under the blue line, and my idle injection (specified and actual) both read about 1.1. I've noticed 3 main things since making this change:

1. Firstly, I'm very pleased to say, there is no noticeable difference in performance. The car still pulls like a train. I was expecting to see a change here. I guess this is down to the dynamic timing not changing despite me adjusting the mechanical timing.

2. The hot start cranking has been reduced by about 95%! It'll now fire up after about 1-2 seconds instead 4-5 seconds. I'm pretty sure that my cranking speed has increased since the adjustment. I can only assume that the engine was giving more resistance before as the pump timing was set so advanced - the knock on effect being slow cranking which in turn causes problems with hot starting.

3. The slow down shudder has also reduced significantly! It was like magic!! The difference between before and after is quite unbelievable really. There is still a very slight shudder at times, but very rarely. I've since adjusted the IQ from 32768 to 32700 (went from 2.8 mg/stroke to 5.1mg/stroke), and as far as I can tell the shudder has now disappeared completely!

So I'm extremely happy with the results. The car does seem to be idling more smoothly too. I have yet to see what difference this will make to my economy but will be sure to post my results up here when I do. I used to reliably get 55mpg every tank of fuel I used.

Thanks

Ben

 

[kooyajerms]

Ben, want to take a log of 04 WOT to redline and show it to us? Glad the adjustment has worked for you.

 

[tdiben]

Yes sure. I take it by WOT you mean wide open throttle? And group 04 in measuring blocks? Will post results up in a few days.

 

[kooyajerms]

Yes measuring blocks 004 is the timing, we can see where its at at 2000rpms and 4000rpms that way. Cheers.

 

[TdiScottie]

I figured I'd post a mileage update since I said I would.

All my tanks have been 48-49 since performing the procedure. Prior, I typically got 46.

By no means am I claiming the new timing setting is responsible. Literally the day after I performed it, winter broke here and we started getting spring temperatures. That is a factor I'm sure. Too many variables to make a claim one way or the other.

Regardless, I'm still happy with it.

 

[RVKazak]

My experience with timing adaptation is very limited although I think it should be posted here.
Recently I had an odd behavior of the timing. I even try to open new thread about http://forums.tdiclub.com/showthread.php?t=35355. Unfortunately I have not received any replies. Fortunately I was able summarize knowledge of the forum to eliminate my problem.
In short version I had 17656 code popping up on me and timing was unstable. By testing varies position IP I found advance timing was introducing a code at elevated RPM but retarded timing was giving me a hard start and unstable reading in basic settings. I spend a week reading a forum and monitoring timing every day. I found two general recommendation for timing question; 1. advance up to the roof of the chart to utilize high pressure combustion and 2. Explained very well by aNut at first post here.
I choose to follow aNut recommendation because it make sense form engineering and user point of view to have wider spread of adjustment in UCU option.
I agree advanced timing will give superior kinematics in engine block specially at high RPM and low loads but it will shift available window of adjustment and partially make it narrow on the low RPM side.
I do not know much about close loop electronics but I would say it is related to late response of the IP to command from UCU (time of mechanical adjustment +time of response from UCU to feet buck from sensors in synchronization with RPM of the ingine). It is easier to adjust “up” when start point is advanced already.
Previously I was staying away from the adaptation of the timing chart. But my first try had eliminate a code and timing is stable now.
I should say car behavior is different. I do not have so much power at the top end of the RPM and shifting has to be slower.
I do not completely understand how shifting timing across graph helped to remove an error code. Please review history of the problem and post your opinion.

 

[RVKazak]

I am sorry Link should be http://forums.tdiclub.com/showthread.php?t=353554

 

[eddieleephd]

I think this link can help some researching in this thread.
IQ Injection Quantity vs. Timing and why the timing in this thread is good for mileage.
http://forums.tdiclub.com/showthread.php?t=339804

 

[Interslice]

I'm a long time reader but first ever post, great thread on a great forum, anyway...

I done 2 tests to investigate the OP theory.

Timing set on red line (RET) I got 43.6 mpg over 1023 miles.

Timing set just below green line (ADV) I got 39.6 mpg over 1215 miles.


With the timing set reterded I noticed much more low end power. With the timing advanced it struggled on hill starts especially with a cold engine (my TDI's a van full of stuff). There wasn't the noticble difference in high end power I was hoping for either.

I'm going to set the timing to just below the blue centre line and do another 1000+ mile test.

 

[sam2007]

I also have tried injection pump timing at the two extremes and setting my 11mm pumped ALH below the blue line >for my setup it works much better way more low end and mid power for free my MPG has not changed. ..will be waiting to see your mpg update then you get the numbers thanks

I'm a long time reader but first ever post, great thread on a great forum, anyway...

I done 2 tests to investigate the OP theory.

Timing set on red line (RET) I got 43.6 mpg over 1023 miles.

Timing set just below green line (ADV) I got 39.6 mpg over 1215 miles.


With the timing set reterded I noticed much more low end power. With the timing advanced it struggled on hill starts especially with a cold engine (my TDI's a van full of stuff). There wasn't the noticble difference in high end power I was hoping for either.

I'm going to set the timing to just below the blue centre line and do another 1000+ mile test.

 

[mcm]

Not sure how useful this is but I just went out and checked the car.. actual timing matches requested, and puts the graph right on the midpoint (blue line.) I regularly see 50-52MPG (2000 ALH jetta)

 

[soup nazi]

Hi guys
I have timed my car sing VCDS but have had my car at two separate Tdi gurus and both of them have told me that its possible, and even preferable, to time them using the old dial indicator method. Anyone had a go at this?

 

[3turboz]

Hi All,
Hope this thread is not so old that nobody will respond. I have actually read this entire thread several times, just wanted to share my experience and ask a follow up question.

On post #125 I detail how I set my timing using the method in the OP with non-VCDS software. I got 37-39 MPG out of my ALH Golf Auto and figured that is about as good as it gets.

At a recent GTG, a member had my car on VCDS and said “hey, your timing is way retarded!” So we set it using just the graph and it was on the blue line. At this time we also minimized EGR function and increased the IQ number a bit.

About a week later I went on a 1,200 mile trip, towing my open trailer with two MX bikes. I had a buddy along and our gear and coolers , tools, fuel, etc. On past excursions of this sort I usually still get my 37-39 MPG (that is why I have the TDI!). On this trip I only got a little over 30 on a couple tanks. The car also felt a little sluggish on hills.

A few weeks later I bought VCDS and checked it out. Timing was still close to blue line, but in measuring blocks the solenoid was pegged at 2.8 and the requested was 1.3 ATDC and the actual was over 3 BTDC. I bumped it down a bit (actual at 1.5 btdc), but the solenoid was still pegged. Ran out of time, but next tank I got back to my 39 mpg! I did notice some changes in the engine also; Quieter at idle and light cruise, more responsive at tip in, and feels like I don’t need to give it as much fuel to get it to move like I want it to. Maybe this is the reason for better MPG?

Still not satisfied, I bumped it a bit more and got the actual down to 0.0, but it is still looking for 1.3 ATDC and the solenoid is still pegged at 2.8. The graph is below the blue line, and it says “timing within spec but slightly retarded”.

So, here are my questions:
I was curious why my ECU is specifying such retarded timing, more that would be indicated by the shots others posted, or as discussed in the FAQ. I looked at adaptation and it has not been messed with, up to temp, etc. My minimum advance is now 0, and if my specified was like most folks it would be matching. Any ideas?

Also, in the OP aNUT says “Notice that I'm not even above the blue! On a cold day with not so stellar fuel in the tank, that apex can be a dotted white line or so above the red.”

I know that fuel temperature impacts timing, but how does fuel quality? (how does it know?)

Thanks!

 

[greengeeker]

Carl, put your egr adaptation back to stock. I bet you'll notice your requested come back up.

 

[3turboz]

Carl, put your egr adaptation back to stock. I bet you'll notice your requested come back up.

I tried that this morning, No change

I also drove the car and noticed that the requested and actual timing, at cruise was 1.7 ATDC to 1.9 ATDC with duty cycle in the 20s, so obviously the minimum advance of 0 at idle can still be exceeded off idle. I think that contradicts the OP and makes me wonder about pump case pressure comments earlier in the thread. Or pehaps I have a problem with the needle lift sensor?

At WOT and high RPM I get actual matching requested and not over 80% duty cycle, so it looks like the ECU is able to meet specs everywhere except idle.

 

[spesh]

I just set up my timing this way, ended up with the timing just a little (and I mean a fraction) above the blue line so timing is pretty much spot on.

However I seem to have lost 3-4mpg since doing it which is a little annoying. Its more likely I've messed something up so any pointers welcome

 

[Joester]

Ok so I tried checking my timing and here are the results.
Here is my static timing graph

I forgot to screen capture when the car was totally cold and at idle, but Specified AND Actual Timing is around 4* BTDC, duty cycle is at an average of 56%
Here is when the engine is warm and at idle

Here is when the engine is warm and cruising at 70mph on a flat highway

I've never quite gotten the mileage I've expected from this car. I average around 40MPG, and while that's nothing to complain about, I feel like my 5 speed ALH can give me a lot more. I've only gotten above 50 one time in my 4 years of owning this car, despite many many 100% highway roadtrips. Usually I get about 45-47MPG if I drive 100% highway, so I feel like somewhere I am missing about 4MPG or so.

May be worth noting: My EGR adaption value is set to the lowest it goes. I did this to supposedly prevent intake clogging. I did not see any change in milage when I did this.

So does this data indicate that I need to change anything? My interpretation is that I need to actually retard the static timing a bit so that It can reach those ATDC values at idle, but I'm no expert.

So any input is appreciated. Thank you.

 

[greenskeeper]

Ideally you'd want the duty cycle to be as low as possible. Are you looking to keep the timing as stock or adapting in vagcom for more advance?

 

[KERMA]

Also, in the OP aNUT says “Notice that I'm not even above the blue! On a cold day with not so stellar fuel in the tank, that apex can be a dotted white line or so above the red.”

I know that fuel temperature impacts timing, but how does fuel quality? (how does it know?)

Thanks!

Fuel temperature affects density, which changes the speed of sound in diesel fuel. The "timing graph" is just a representation of how the pressure pulse travel time changes according to the speed of sound vs temperature.

Hotter fuel = less dense = slower speed of sound = more travel time = pressure wave arrives later = injector needle lifts later = timing graph is more "retarded" at the needle lift sensor for the same physical plunger position at the injection pump.

Colder fuel = more dense = faster speed of sound = less travel time = pressure wave arrives sooner = injector needle lifts sooner = timing graph is more "advanced" at the needle lift sensor for the same physical plunger position at the injection pump.

The difference is the travel time of the pressure pulse along the injector line between the injection pump plunger and injector needle being forced open by the pressure wave. (we are talking a difference of a few microseconds making that much affect)

fuel quality can affect IGNITION DELAY which means the fuel physically takes more/less time to actually ignite and cause a pressure pulse against the piston after it's actually injected. Little known or considered fact: fuel does NOT ignite at the exact time it's injected, but some time after. Anything that affects this ignition delay has a profound impact on every aspect of how the car runs, fuel economy, noise, power, smoke, you name it. Preinjection softens the blow so to speak and adds forgiveability so if things are a bit "off" it's not as noticeable as it was in the older diesels, but it also means that cause and affect are not as tuneable "by ear" so there's a "false" sense of "nothing wrong"

When we speak so freely and loosely about "timing" we fail to consider that we are only discussing the "start of injection" (SOI) or the physical injection event, only discussing the timing of the physical introduction of fuel into the cylinder. The actual combustion BURN and subsequent cylinder pressure happens SOME TIME AFTER SOI. But we can only directly control/observe SOI so that's what's popularly discussed and it's what the mechanics adjusts.

So, the car itself does not "know" about poor quality fuel, but the driver may notice the car is running better/worse etc.

FWIW please restore EGR adaptation to stock 32768 if you want better fuel economy.

 

[B100]

Is there some target range we're looking for on the Cold Start Injector Duty cycle? Mine doesn't drop below 50%, even when engine is warmed up... is it directly affected by static or adapted timing?

 

[greenskeeper]

The duty cycle is how much the ecu is working to get the requested vs actual to match. The higher the number the more retarded timing is when you compare requested vs actual. Ideally you want the duty cycle to be at 2.9% and actual and request to match.

 

[colinstone]

Recently changed my cambelt etc at 118k miles on an 2001 110bhp ASV engine.
Had a look today at 004 etc and results are:

Idle RPM 903
Coolant 63C
Specified start 0.4 BTDC
Actual start 3.5 BTDC
Cold start valve 2.8%
Fuel consumption 0.6 l/hr

Fast idle RPM 1974
Coolant 44C
Specified start 1.1 BTDC
Actual start 1.1 BTDC
Cold start valve 2.8%
Fuel consumption 2.1 l/hr

I will repeat after a run with car a normal operating temp, but I guess I could retard the timing a nudge to get the idle figures to match.

Any comments out there?

Thanks.