Results are in 3-4 MPG increase!

I have for the first time (in the 5 years of owning my '98 Beetle) broken the 50mpg mark! I advanced my timing in adaptation and noticed an increase in performance as well as flawless, smokeless cold starts. While the car seemed to like the advanced setting and my gut feeling was that I would get better mileage I wasn't sure especially due to the fact that the new more eager to rev attitude of the engine inspires me to take off more often. Well, I have never gotten better than 47mpg (and that was using cruise) until now. I drove to Fort Knox TN for a job this week and got 50.63 MPG. This was without cruise, often over 80mph, and while driving into strong headwinds with on and off rain storms for a good 2 hours of the trip. I love it!!!!

How many degrees advanced did you go? I just dialed in +1.5. I can't tell any difference. I also adjusted my base timing to 65/110 from 40/105. We'll see what kind of mileage I get when I leave for Florida tomorrow. Same trip this past October I averaged 45 mpg Imperial.

I have full advance. 5 degrees. Is it 33268 I think?
If you are going on a trip advance it all the way you will have great results. I first had it half way (2.5 degrees) and noticed better starting but didn't check mileage at that point. I kept it there for a few weeks then went all the way. It is working great. Try it you'll like it.

I thought it was a big NO-NO to advance timing this way. Unless I am reading the FAQ's wrong???

I changed the timing before the last fill up. I went the full 5 degrees. My wife wanted to know what happened to her car she has now driven more than 650 miles and the low fuel light has not yet come on. During her normal commute cycle I fill it every 600 miles; and have been getting about 44 mpg. I looked at the car at lunch and it still has one more hash mark to go before the low fuel mark. I think it will probably go at least 700 miles before the warning bell rings. Until I refuel I won't know for sure but it appears that advancing the timing has increased the fuel economy by at leat 10 percent.

I thought it was a big NO-NO to advance timing this way. Unless I am reading the FAQ's wrong???

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You're reading it right, it just needs to be revised. Adjusting timing in adaptation is not a big no-no.

Tuning boxes can not alter injection timing. Tuning boxes plug into the pump harness that has the wires for fuel temp (G80), quantity adjuster (N146), and modulating piston displacement sensor (G149).

If you are gonna mess with timing, you are gonna need to interface with the Commencement of Injection solenoid valve (N108), the Needle Lift Sensor (G80), or crank position sensor.

I doubt that a tuning box would use fuel temp as a means to meddle with timing. It would be very unreliable/unrepeatable.

What other options are there. This is definitly something I would love to do. Do i have to find someone with a VAG?

Can you explain in detail how to perform this
mod using vag-com??

I would love to get another 3 or 4 mpg!!

First you go to login (12233) then you go to adaptation then you type in # 04 then you type in the highest number which I think is 33268 (not positive without checking mine but it should be 500 more than the value set from the factory) then you push test then save. You will hear the sound of the engine change a little. (slightly more diesel clatter)

<font color="red"> PLEASE BE FORWARNED. IF THIS MODIFICATION PUTS YOUR TIMING OFF THE SCALE, IT COULD CAUSE SEVER ENGINE DAMAGE!!! YOU HAVE BEEN WARNED!!! </font>

First you go to login (12233) then you go to adaptation then you type in # 04 then you type in the highest number which I think is 33268 (not positive without checking mine but it should be 500 more than the value set from the factory) then you push test then save. You will hear the sound of the engine change a little. (slightly more diesel clatter)

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This is flerting with disaster.

There is no evidence that it will damage anything. I for one feel that you can cause more damage with overboosting from chipping and lots of people have done that. We can use the arguement that if the engine were designed for that much boost VW would have done it out of the box. (I am not telling people not to chip. Just my opinion.)The timing advance is purely an emissions issue which is an individual choice like the EGR mod or CCV mod. When you advance the timing in adaptation you are running even leaner which increases NOX emissions. VW would have had unmanageable amounts of soot in our intakes sooner therefore they retarded the timing some (at the expense of fuel economy) to combat the issue. I for one can tell by the way my engine starts/runs/performs and now the added MPG that this is the optimum setting for the engine. Before it was always that little bit off. That little sputter/smoke not quite right that you knew could be fixed but there wasn't anything "wrong" with the engine. Now it finally (after 5 years) runs like I knew it could/should.

There is no evidence that it will damage anything.

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That is not true... A few months back someone destroyed their engine doing this mod

$2.00 for three non-stretch injection pump bolts and 1/2 hour max of you time (if you're slow and way past anal like me) is not much to have it adjusted the correct way... MECHANICALLY!

$2.00 for three non-stretch injection pump bolts and 1/2 hour max of you time (if you're slow and way past anal like me) is not much to have it adjusted the correct way... MECHANICALLY!

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eluwak,

Can you point us to a thread or FAQ that details how to perform this adjustment?

Thanks!

I'm not talking about the basic mechanical timing I am talking about advancing the ECU's timing. My mechanical timing (using the three bolts etc...) is fine.
Who destroyed their engine anyway? You can't just throw that out there. What are the details?

8. Advancing the Injection Timing

There is a misunderstood impression that more timing advance can produce more power. The correct statement is that the *optimum* amount of timing advance will produce the most output, and anything more or less will have adverse effects. Every 2 degrees of timing advance beyond the so-called "minimum advance for best torque" raises peak cylinder pressure by about 15 bar (about 10% increase from stock) and raises piston operating temperature by an unknown amount. Both of those are headed towards holes in pistons if taken too far.

There are two different "injection timing" settings. There is a mechanical adjustment procedure which involves setting the proper mechanical timing of the pump based upon information from VAG-COM's "group 0 basic settings" display, following the procedure in the shop manual. There is also an ECU adaptation channel which can be adjusted using VAG-COM. These procedures are NOT INTERCHANGEABLE and have completely different effects. The mechanical adjustment procedure following the shop manual (and preferably setting the timing within specs but in the upper range of the graph in the shop manual) is the right thing to be doing. Never touch the adaptation channel ... always leave this at stock specifications.

Installation: Not really an "installation". The correct mechanical adjustment procedure for the pump requires VAG-COM, the shop manual (for specification chart and proper procedure) and a selection of wrenches and sockets. Don't adjust it if it's already within specs, and very small adjustments make a big difference. The incorrect VAG-COM adaptation method only requires VAG-COM, but you shouldn't be doing it anyway, so forget that the possibility exists.

Advantages: Setting the injector pump mechanical adjustment so that it is close to the top of the specification range (but still within specs) ensures that under conditions when maximum timing advance is requested (e.g. full load), the pump can actually deliver the requested amount of timing advance. If it can't deliver maximum advance under those conditions, the result will be more smoke, higher exhaust temperature, and reduced efficiency. Proper mechanical timing also makes the engine easier to start under moderate temperature conditions, since under those conditions, the automatic timing adjustment mechanism is not operating. The (non-recommended) VAG-COM adaptation method increases requested timing advance under all speed and load conditions. Advance too much and run the engine too hard ... and the result will be severe engine damage, so don't do it!

Disadvantages: There are no disadvantages to having the injector pump's mechanical timing exactly where it should be! But for the VAG-COM adaptation adjustment ... You are your own warranty, and this is something that is headed towards holes in pistons.

Cost factor: Next to nothing, if you do it yourself and have VAG-COM. (Some models require the bolts at the injector pump sprocket to be replaced, which will cost a couple of bucks.)

Cautions specific to this modification: To do the proper mechanical adjustment, you need to know which way to turn a wrench and have the required "mechanic's common sense". If you don't know which way to turn a wrench, then leave the work to someone else. You shouldn't be doing the VAG-COM adaptation method due to the possibility of severe engine damage.

Suggested modifications in parallel: Irrelevant.

"Bang for the Buck": Irrelevant, you should have the mechanical pump timing correct anyway. BAD NEWS, for the VAG-COM adjustment method, due to potential engine damage.




I can't believe Go Faster or Fred would put this in the TDIFAQ's without reason.......

What she ^^^ said

The procedure is in the Bentley manual and probably in the A4 timing belt change procedure in the article section.

eluwak,

Can you point us to a thread or FAQ that details how to perform this adjustment?

Thanks!

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I searched a bit earlier for the destroyed engine thread but am having trouble finding the right key words...

First time over 700 miles on jetta wagon with automatic. With mixed city/highway commute I managed 46.1 mpg. I have been getting 42 mpg commuting pretty consitently since new (now at 29,000 miles). Best had been about 46 on extended highway trips in Canada where the speed limit is lower and I was enjoying the sights. So I'm getting 3 to 4 mpg better.

There seems to be a lot of concern from the performance people. Now if I drove the car at WOT all the time I might be concerned about increased temperatures and pressures. The jetta is not a race car or a heavy duty hauler, so putting along at 50 to 70 mph on the freeway, I don't think that there is substantial risk.

My other ride is a Cummins ram, I have done substantial mods to it and driving around town there is no change in EGT or oil temerature. I only see changes at WOT either towing a heavy load up steep hills, when the mods bring in the substantial extra power.

I searched a bit earlier for the destroyed engine thread but am having trouble finding the right key words...

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eluwak,

Was this the thread you were talking about: TDI Tear down

$2.00 for three non-stretch injection pump bolts and 1/2 hour max of you time (if you're slow and way past anal like me) is not much to have it adjusted the correct way... MECHANICALLY!

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eluwak,

Can you point us to a thread or FAQ that details how to perform this adjustment?

Thanks!

Click to expand...

It's in the TDIFAQ's as well!

Boundless didn't you say you were running 5% BTDC on your car. And had positive results. I think the thread they are taking about was about one guy who have advanced his timing Via Vag-com then blew it up But, never did prove it was the timing that did it.

I understand that there will be bad effects from advancing the timing too far due to the fact that the piston gets rammed on its way up by the explosion happening too early. A situation like that would be noticed by reduced performance and MPG and loud clattering. If the engine is experiencing better perfornace and MPG and sounds good then that isn't the case. Same thing is true with a gas engine. The best performance and mileage is achieved by keeping the engine at the edge of pinging. If the engine is pinging all the time not only is it bad for the engine but you get reduced mileage and performance. My engine is starting quickly and smoke free, running smoothly, is free reving, is getting better mileage, and sounds good. All signs of a happy engine. Before the advance I had questionable starts with smoke, slight roughness and jerkiness when I would drive off with light throttle initially in the morning. I also had questionable starts sometimes when the engine was fully warm. None of this is the case now.

Yep, I'm running advanced, and loving it. Never going back.

Not too many TDIs have blown up. I just know of Ol' Silver. That was not from advanced timing. So where is that thread on the TDI that blew due to advanced timing?

Wow!! You folks really crack me up.

That section 8 quoted above is in need of some serious updating.


Let's see... Running the basic settings of the pump to 'the top' is supposed to 'advance' the timing such that you get more HP, MPGs, and less smoke. Tuning boxes are supposed to advance timing. Chips are supposed to advance timing. And yet all these things that are believed to advance timing are supposed to be good, such that they are well sought after mods. And used in combinations!!!!

Well, basic settings doesn't advance timing the way it is presented. At best, it advances timing during cranking. Tuning boxes plug into the pump fueling controls and don't interface with the NLS or COI, so they can't affect injection timing. And remember, a tuning box fakes the ECU out so the ECU cannot recompute an advanced timing for the additional fuel it is enabling. That's why tuning boxes tend to smoke. BTW, the ever popular IQ adaptation changes injection timing because it alters the IQ computation - depending on which direction you go with the fuel.

I haven't fully investigated the affect chips may have on timing, and probably won't bother. It's been said that chips advance timing, but I won't believe that unless I do the testing. After all, it has been said repeatedly, and in the TDIFAQ, that tuning boxes advance timing, even though they can't. And I mean independently of fueling, like the timing adaptation mod does.


One thing in the TDIFAQ that is correct is this:

There is a misunderstood impression that more timing advance can produce more power. The correct statement is that the *optimum* amount of timing advance will produce the most output, and anything more or less will have adverse effects.

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Now it is well known that the TDI is retarded from the factory. The OEM timing is retarded from the *optimum* timing for HP & MPG. Therefore, advancing timing from the OEM settings does not guarantee that the sky will fall. You might actually end up at the optimum for MPG & HP!!!!


The other thing that y'all have to get familiar with is the timing spec:

Idle: 3° ATDC to 4° BTDC

3,000 RPM: 8° to 12° BTDC

AND THESE ARE RETARDED FROM WHAT WILL PRODUCE OPTIMUM MPG OR HP.

Now every car I've VAG-COM'ed was set to 0.4° at idle.


Gary, from your quote:

PLEASE BE FORWARNED. IF THIS MODIFICATION PUTS YOUR TIMING OFF THE SCALE, IT COULD CAUSE SEVER ENGINE DAMAGE!!! YOU HAVE BEEN WARNED!!!

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What scale are you talking about?




Oh, and this mod (advancing timing in adaptation) will hole a piston? Well, Ol' Silver supposedly had wa-a-a-a-ay advanced timing that bent the connecting rods, right? Yeah, you know, that 2° and 15 bar stuff we keep seeing over & over. Well, those pistons from Ol' Silver were not impinged upon by a flame at all... in other words: The pistons were not damaged by an engine that was supposedly set up too far advanced. But then, maybe Ol' Silver didn't have over-advanced timing... but what bent the rods? Never mind... hehehe...


MaryP,

I can't believe Go Faster or Fred would put this in the TDIFAQ's without reason.......

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There has been good reason to revise the FAQ before...

eluwak,

Can you point us to a thread or FAQ that details how to perform this adjustment?

Thanks!

Click to expand...

It's in the TDIFAQ's as well!

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No Mary, it is not...!

What is in the FAQ is the description you cut and pasted above. That describes what it is, not how to do it...

eluwak,

Can you point us to a thread or FAQ that details how to perform this adjustment?

Thanks!

Click to expand...

It's in the TDIFAQ's as well!

Click to expand...

No Mary, it is not...!

What is in the FAQ is the description you cut and pasted above. That describes what it is, not how to do it...

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Section 7. K. of the TDIFAQ's:


Setting the Injection Timing - Injector Pump Mechanical Adjustment - A VW specific scan tool such as VAG-COM is required for this procedure. It cannot be done by any other method. The mechanical adjustment technique used for previous generations of VW diesels, which used a mechanical fuel pump without electronic control, is not suitable for the electronically controlled TDI injector pump.
With the engine warmed up and idling, connect the diagnostic tool, and select the engine control module. At this point, one of two different procedures is necessary, depending upon whether you have the proper factory service manual for your particular vehicle.

If you have the factory service manual, select "Measuring Blocks", group 0, then select "Basic Settings". The glow plug indicator lamp will begin flashing at this time (this is normal). Do NOT forget to go into "Basic Settings" because this procedure is completely invalid if measurements are taken outside of "basic settings". Take note of the 2nd and 9th numbers in the display. Locate the chart in the factory service manual which shows the proper relationship between these two numbers. Go across the chart with the 9th number then up the chart with the 2nd number and make sure it is within the shaded area. It has been found through experience that these engines have better cold starting characteristics if the setting is within the upper half of the shaded area. If it is good ... don't do anything further. If the second number is below the recommended range, you need to make a mechanical "advance" adjustment (see below). If the second number is above the recommended range, you need to make a mechanical "retard" adjustment (see below).

If you don't have the factory service manual, select "Measuring Blocks", and go to group 4. Do NOT use "basic settings" for this method. The displays show the requested injection timing, the actual measured injection timing, and the duty cycle of the advance solenoid. At warm idle in neutral, requested timing should be between 0.4 and 2.0 degrees BTDC. If the actual timing is not more than roughly 3.0 degrees BTDC, and the duty cycle of the advance solenoid is not more than 10%, the timing is good ... don't do anything further. If actual timing is more than 3.0 degrees BTDC, you need to make a mechanical "retard" adjustment. If the duty cycle is more than 10%, you need to make a mechanical "advance" adjustment.

If you have an A3 or B4, you need to rotate the body of the injector pump "forward" to retard the timing and "backward" to advance the timing. Stop the engine. Remove the upper timing belt cover. Rotate the engine by hand (shifting trans into 5th gear and pushing the whole car works) such that the two nuts at the rear and bottom of the injector pump flange can be reached through the access holes in the pump pulley. Loosen these two nuts by 1 turn, loosen the bolt at the top front of this flange 1 turn (accessed from outside, not within the pulley). Loosen the bolt located at the opposite end of the pump below the four injector lines. With a 17mm wrench, loosen by 1/2 turn the injector lines on the end of the pump. Now you can rotate the entire pump housing in the required direction (make VERY SMALL adjustments) then tighten and reassemble everything and recheck the timing.

If you have an A4, you need to remove the upper timing belt cover and adjust the relationship between the inner and outer parts of the injector pump pulley. To advance the timing, the inner part of the pulley (together with the pump shaft) needs to move "forward" with respect to the outer part of the pulley. To retard the timing, the inner part needs to move "backward" with respect to the outer part. The 3 bolts which secure the two parts of the pulley together may or may not be "stretch bolts" that must be replaced every time you do this ... so it's a good idea to get 3 new bolts just to be sure. Make all the adjustments using the original bolts, then replace the old bolts with the new bolts and torque them one at a time.

Boundless,

The scale is the scale printed in the Bentley guide... My concern is the "open" statement that you set the advance to the maximum... without any consideration of what the "basic" setting is...

You (and the rest) may believe what they want... It's not my engine...

Gary M

Gary I think you are misunderstanding. The "basic" timing setting is set correctly (within the Bentley scale) It is the adaptation timing that is set to the maximum which is +5 degrees. No body is suggesting that you crank the hub of the injection pump all the way up. You can't do that anyway because either the engine won't run or you will get a CEL light.

I understand that there will be bad effects from advancing the timing too far due to the fact that the piston gets rammed on its way up by the explosion happening too early. A situation like that would be noticed by reduced performance and MPG and loud clattering. If the engine is experiencing better perfornace and MPG and sounds good then that isn't the case. Same thing is true with a gas engine. The best performance and mileage is achieved by keeping the engine at the edge of pinging. If the engine is pinging all the time not only is it bad for the engine but you get reduced mileage and performance. My engine is starting quickly and smoke free, running smoothly, is free reving, is getting better mileage, and sounds good. All signs of a happy engine. Before the advance I had questionable starts with smoke, slight roughness and jerkiness when I would drive off with light throttle initially in the morning. I also had questionable starts sometimes when the engine was fully warm. None of this is the case now.

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Just a few points of clarification, cage. First, diesels don't "ping" like gas engines. Ping occurs when a hot point in the combustion chamber initiates localized pre-ignition. A diesel engine injects its fuel after the compression of the rising piston has heated the intake air to a temperature high enough to ignite the diesel as its squirted into the combustion chamber. Furthermore, as one advances the injection timing on a diesel engine, the piston is further from the top of the cylinder at the moment of injection. The purpose of advancing injection timing is to bring the moment of maximum cylinder pressure to the optimum point to assure max power and efficiency. Setting your injection timing to the proper point does all those wonderful things you mention. Advance it too far, though, and the engine gets growly and loses power. But melt holes in your pistons, as someone wrote above? Gimme a break. Can't happen with stock or even "normal" oversized injectors that are working properly.

Setting the injection timing to the proper point sounds like quite the ticket, though. One more excuse to buy a vag-com...

Advancing the injection timing raises peak cylinder pressure. There can be no discussion about this ... it is a fact! If more fuel has been burned at the time TDC is reached, the cylinder pressure is higher.

The engine has a safety factor against peak cylinder pressure based on stock condition ... all production engines (and in fact, all engineered systems of any sort!) have safety factors in them.

We don't know what the safety factor is.

Advancing injection timing uses up some of the safety factor. Increasing boost pressure uses up some of the safety factor. Adding bigger injectors uses up some of the safety factor. There is a limit to how much cylinder pressure the engine will take. The fact that there IS a limit, and that the limit can be reached with catastrophic results, has been demonstrated. But we don't know precisely how much the limit is.

If I'm gonna do stuff that raises cylinder pressure I'm gonna select mods that have the most benefit for the lowest possible increase in stress ... and advancing the timing ain't the prime choice, it's rather close to the bottom of the barrel.

Keep in mind that the TDIFAQ, by its very nature, MUST present a "conservative" viewpoint. I wrote that thing, and I don't want some idiot cranking injection timing to the max on top of the chip and huge injectors that they've already added, and then trying to haul a trailer over a mountainside pedal to the metal, and then blaming ME.

Boundless has a car which is bone stock in every respect but this, and it's an A3 which runs lower stock boost pressure than an A4. I don't think it's gonna blow up because of this. But anyone with bigger injectors or more boost than stock for any reason had better be careful about this.

I await patiently for the first time some idiot with monster injectors tries this stunt and blows it up ... You can be darned sure it won't be this puppy ...