# ??? Digi lag



## duscrub20 (Jan 27, 2007)

I believe i have what is know as digi lag. My ques is does anyone have suggestions on correcting or fixing this. I know i can adjust the MAF sensor screw. Will that be sufficient or a waste of time. and is there anything else i can do besides a swap? Thanks


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## B4S (Apr 16, 2003)

the only way to eliminate digi-lag is with a chip.


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## duscrub20 (Jan 27, 2007)

I have the digifast chip. Maybe another issue? When i go to take off in first. It doesnt want to move. It takes a while to get up to 2000 rpm then finally picks up. Same thing if say im taking a turn in second and then mash the throttle to pick up speed. It doesnt wanna move like im tied to a tree.


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## ps2375 (Aug 13, 2003)

Do you have the timing set correctly?


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## duscrub20 (Jan 27, 2007)

Almost 100%. Does that sound retard or advace to you?


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## ps2375 (Aug 13, 2003)

It sounds like it is retarded. Hence no power.


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## duscrub20 (Jan 27, 2007)

So that produce no power at low rpm or all the way through


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## ps2375 (Aug 13, 2003)

reduced power at all engine speeds, but more pronounced at low rpm's cause the ecu is adding less at low rpm's.


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## duscrub20 (Jan 27, 2007)

K im gonna go mess with it. Ill let u know. Thanks man


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## ps2375 (Aug 13, 2003)

Don't "mess with it", set it following the proper procedure. I have not had to deal with many digi cars, but I do know that it has a specific procedure for setting the timing, and if that is not followed, the timing will be wrong.


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## WaterWheels (Aug 14, 2005)

duscrub20 said:


> I have the digifast chip.


 The DigiFast chip will not fix the lag. In fact no home brewed trick will fix it as it is programmed into the ECU. There are two chip sellers that I know of that know what causes the lag, explain it to their customers and sell chips that are supposed to remove it. SNS is one and AK Racing is the other, maybe there are more. The chips are not cheap, AK is about 450€ and the SNS I don't know, but if they correct the problem I guess they are worth the money. Both companies advertise there products for Digifant I, but the programming is I believe is done to all Digifant based systems, Digifant II and DigiJet. I am still waiting for a 100% positive answer to that part.


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## duscrub20 (Jan 27, 2007)

I advance the timing a lil bit by using the didtributor. It helped a lil but now im pinging. I already run 93 in it so im not running 110. Maybe ill just back it back off and leave it alone. I pulled the plastic cap off of the MAF. Which screw do you adjust the phillips on top or the bolt on the side.


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## ps2375 (Aug 13, 2003)

There is only one method for setting the timing on digifant, did you use that method? It is described in detail in the Bently Manual for this car.


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## Glegor (Mar 31, 2008)

you have to do the timing a VERY specific way. its not like setting the timing on an old VW, or a small block chevy.. 

you gotta dis-connect the blue CTS 
rev the engine past 3k rpms 3x 
stand on your head 
shotgun a beer 
pull out timing light 
fart 
set timing to the mark, and there should only be one mark on a DIGI flywheel 
curse your timing light because its not working right 
throw timing light across garage 
tighten down your distributor 
and your done!!! 

seriously tho, with digifant, if you dont set the timing to the spec the computer tune is set up for, then it can NEVER run right. because the ECU knows that timing should be set to 6*, and when its not, it freaks out..


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## duscrub20 (Jan 27, 2007)

Best info ive got ever shotgun a beer. I knew thats why i couldnt get it right!! Nah. Thanks man your info is spot on from what i just read in the bentley. What a pain in the ass. Never used the timing gun on mk2 vw. Mostly pretty easy to get i right without it. But im gonna try doing it the right way. I have it dialed pretty good now from trial and error. But i want it perfect. Thanks for the motivation


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## ps2375 (Aug 13, 2003)

:facepalm:


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## WaterWheels (Aug 14, 2005)

duscrub20 said:


> . . . What a pain in the ass. . . . But im gonna try doing it the right way. . . But i want it perfect.


 Yes, "setting the ignition timing on Digifant" is a messy procedure and time consuming. But it is just that, *setting the ignition timing* and has nothing to do with minor adjustments. Once the basic setting is done you can make minor adjustment just like any other car. After all, the ignition distributor is really no different from many other VW models and the ECU does not and has now way of knowing the degree of advance you have set it to. Digifant seems to work just like the other VW engines in these year cars in that 8 - 10 degrees works better that the factory 6 degrees. 

Problem is that the lag can not be removed by playing with timing or mixture. Yes you can mask it a little and reduce the feel by doing some tinkering, but it will always remain. It is in the programing and not the fuel or ignition timing MAP. VW programmed the system to keep reading the Lambda sensor (O2 sensor) for 1 to 3 seconds after the wide open throttle switch has been activated. At that point it will go into open-loop and run off the programmed MAP for fuel. Once the WOT switch has been released it "re-sets" and the next time you go full throttle it does the delay again. Some kind of safety feature I guess which was maybe well intended but stupid. 

"I pulled the plastic cap off of the MAF. Which screw do you adjust the phillips on top or the bolt on the side." 

I suggest you please do a search and read up on this before going any deeper. It does have an effect on system which use vain type air flow meters but with everything in life there are two sides to every coin. Before you make a mistake which can not be corrected, read a few articles and be sure of what you are doing.


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## ziddey (Apr 16, 2006)

Wbat you are describing does not sound like typical Digifant lag. 

Vacuum leaks? Does it do it cold and hot?


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## duscrub20 (Jan 27, 2007)

I do alot of reading and research and asking and trying. I think i went to far into this to get rid of lag. The timing is good. Its just that lil tinkering to get it perfect. If the lag i feel cannot be eliminated due to a stock map at WOT. then i consider it to be running perfect. Throttle response was good and and got a little better by turning the gear three clicks in the MAF. The reason imgoing to far is i just want it dialed in before i throw my 2.0 16v on digi in my car thats all. Im not an engineer but i have plenty of experience with mk2. Ive done 16v digi once before and i have everything laying around to do it again. I want that xtra 30 HP im not getting with it on the eng stand. Thanks for all your helps guys.


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## Glegor (Mar 31, 2008)

duscrub20 said:


> I do alot of reading and research and asking and trying. I think i went to far into this to get rid of lag. The timing is good. Its just that lil tinkering to get it perfect. If the lag i feel cannot be eliminated due to a stock map at WOT. then i consider it to be running perfect. Throttle response was good and and got a little better by turning the gear three clicks in the MAF. The reason imgoing to far is i just want it dialed in before i throw my 2.0 16v on digi in my car thats all. Im not an engineer but i have plenty of experience with mk2. Ive done 16v digi once before and i have everything laying around to do it again. I want that xtra 30 HP im not getting with it on the eng stand. Thanks for all your helps guys.


 the 16v is going to need a different, more aggressive tune anyways.. so your kinda wasting your time tuning the 8v, if you ask me..


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## duscrub20 (Jan 27, 2007)

Ease up cowboy im takin my time! My MS is being wired together in the meantime!


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