Static timing randomly went retarded, lumpy idle out of no where?

iluvmydiesels

Veteran Member
Joined
Nov 21, 2015
Location
phila area
TDI
AHU
static timing refers to mechanical timing, when you bring engine to a point. this will be crank TDC, then cam TDC, and for us is the timing pin in pump.
so id like you to clarify what you mean as your static timing. it seems your VCDS, which is the inj pump timing. you in recent post stated your unable to check the mechanical timing. this would be a good starting point to check,verify first. then move up the check list, which would include air in your fuel system, also have you changed out fuel filter? this can cause stumbling problems. perhaps could seem to come up on VCDS graph as a timing change, when something else (ie bad fuel filter) is the culprit. fyi air filter needs to be changed usually.
you seem to have some fixation for fuel temp. we cover engine temp here, if its up to temp VCDS will,should read. fuel temp is handled by the ecm & your VCDS. i dont really see its importance for this discussion.
another point that power service pretty much suks, i dont know what you thought you were accomplishing using that cr*p. use better stuff. 1 new fuel filter, then run a full can of diesel purge in a full tank of fuel. i suggest a better fuel conditioner. im not really a fan of power service, and i personally am of the opinion mainly it doesnt do much(beside the fuel system lube its supposed to perform, then again there are much better choices, not as many may be available at your local crummy auto parts store).
 

Giberish33

Veteran Member
Joined
May 30, 2017
Location
Montreal, Qc
TDI
1997 Jetta TDi 1z
iluvmydiesels, you are correct that at the moment I'm not able to check the tdc marks and you are also correct that I'm referred to the injection pump timing. I thought it was referred to as "static" because its mechanically adjusted by rotating the IP sprocket and should stay there, where as to me dynamic would refer to the requested and actual in group 004. It sounds like I have been using the incorrect terms... But yes the timing shift I'm talking about is the injection pump timing.

changed the fuel, oil, and air filters all just before the winter maybe ~3-4000kms ago. I have always seen maybe 1 or 2 bubbles every couple of minutes no constant stream of air going through the lines, I guess my thermo-t could be changed just to test.

The reason I'm bringing up fuel temp a few times is because in the TDI timing graph the 2 lines that intersect to show the IP timing one is a fuel value and the other is a timing value so depending on fuel temperature that will change where the 2 lines meet each other on the graph. Even if the timing graph means nothing until engine coolant is hot it still is reading about 10 points lower now than it was a few months ago. I have not done any work to the car since the fall and have done nothing but fill up with fuel and drive. I don't know if it is normal for the IP timing to move overtime on its own.

Again like I mentioned I noticed that my stabilization values one of them is now well into the negatives where as before (in the summer / fall of last year) all values were in the positives. I know already that my injectors are getting a little tired.

What additive would you recommend that I use? Stanadyne or something else? I'm only running power service because its easily available.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
1 new fuel filter, then run a full can of diesel purge in a full tank of fuel.

That’s a way to severely dilute/waste it. Let the IP pull and return the full strength Diesel Purge, to the can. Use a cheap inline filter, if it makes you feel better. I’ve substituted diesel and ATF, for Diesel Purge with pretty much the same results. ATF has a lot of detergents in it.

Don’t expect miracles with these products. They help with pumps that have sat for a while. If you have reason to believe there may be gummed up fuel in your IP, go for it. If not, I guess it can’t hurt.

-Todd
 

Giberish33

Veteran Member
Joined
May 30, 2017
Location
Montreal, Qc
TDI
1997 Jetta TDi 1z
T I’ve substituted diesel and ATF, for Diesel Purge with pretty much the same results. ATF has a lot of detergents in it.
I know there is lots of debate on additive use and people running things like 2 stroke oil to help with lubrication. Just out of curiosity is there a particular kind of atf? synth vs regular?

I've read about people using this mix straight through the pump for like a diesel purge cleaning but then again lots of people say atf does nothing and that new atf doesn't contain nearly the amount of detergents older atf did. But by the same token tons of people swear by the use of 2 cycle oil and its supposed cleaning abilities while others say it has no place in a 4 stroke diesel motor. I like hearing anecdotal evidence rather than people talking about theories or opinion.
 

iluvmydiesels

Veteran Member
Joined
Nov 21, 2015
Location
phila area
TDI
AHU
the atf trick is for pumps in a lot of need. i used it, straight atf (iirc) and let squirt out other end of pump.
some esp older diesel owners, with mechanical pumps can well use esp ashless 2stroke oil for fuel condidtioner/lube.
the straight bottle of diesel purge 'bottle fed' to an inj pump, on a running engine is concentrated, for *trying* to clear up bad pump problems, that otherwise may take up such as pump replacement or a pump tear-down.
i dont think running a can of purge in a full tank of fuel is 'severely diluting'-it, its a maintenance recommendation, the other is to run full concentrate, if a doubt or you want more concentrate, add to 1/2 tank, or ~5/8-~3/4tank. a full tank is a standard treatment. its less concentrated (in a full tank), and safer, for the most part. i really feel it works quite good, for what its intended, and over the years have seen results by using, either full concentrate, if needed, or in a ~5/8 to ~3/4 to a full tank.
to run motor out of can, you make you a rig-up, i find go to a plumbing shop, get a hose fitting, i think inlet fuel line is 3/8" so you need a 3/8"to3/8" fitting (i like brass), some fuel hose, run that fuel hose to bottom of can, can put a filter inline here, take another hose, (fuel, check for size) run off of inj pump return, run this hose to bottle, start engine, run at different speeds, run out bottle. i just prefer adding a can to a full tank as more general maintenance, and less concentrate.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
I know there is lots of debate on additive use and people running things like 2 stroke oil to help with lubrication. Just out of curiosity is there a particular kind of atf? synth vs regular?
I've read about people using this mix straight through the pump for like a diesel purge cleaning but then again lots of people say atf does nothing and that new atf doesn't contain nearly the amount of detergents older atf did. But by the same token tons of people swear by the use of 2 cycle oil and its supposed cleaning abilities while others say it has no place in a 4 stroke diesel motor. I like hearing anecdotal evidence rather than people talking about theories or opinion.

Sounds like you may be better off doing nothing. Plenty of people run only d2 from the pump and have no complaints.

You’re coming to an Internet forum for help and advice... you’re going to get a lot of theories and opinion.

-Todd
 

Dieselfiend

Veteran Member
Joined
Jun 21, 2009
Location
Boise, ID
TDI
1998 Red TDI
If you haven't already solved your issue, with that kind of milage, my money is on the stretch bolt (crank bolt). I'd reset your timing, drive it around, then recheck time. It will jump around. That meaning that one measurement you might be advanced, another you might be retarded or you might all of a sudden be having cold start issues.
Same exact thing happened to mine at around the same milage.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
SOLD 2010 Touareg Tdi w/factory Tow PCKG
Damn ok, thanks Vince. I guess I over estimated the amount of timing can be offset by any stretch. Like I said the last time I checked timing it was mid 40's reading dead on in vagcom, now timing is in the mid to low 30's given the same fuel and coolant temps. Pretty much my plan at this point is to reset the timing and monitor it. I can't seem to see any kind of wobble in the harmonic balancer, should I be looking at first start up when things are cold or when the motor is already warmed up / doesn't even matter there would be wobble at all times?

Also weird to me is that cyl 3 (I know this is really cyl 4 in comparison to cyl 3) is showing negative numbers for injection deviation, this summer all cyl were in the positives. Again all of this could have been progressive and I only realized now but I'm just worried that something is actually not ok. I take great care of her otherwise, consistent oil changes, filters, diesel additive and taking the bi-weekly WOT run onto the highway.

*side note: have not had the same lumpy idle since I tightened down the injector retaining clamps and bumped the IQ a little, maybe unrelated but as of now I'm only trying to figure out the reason / correct the drop to retarded IP timing from dead on center*
Just for a data point: if one or more of those hold downs was loose, or you re-used the copper washers without re-annealing them, it could act fine when cold, but get loose upon warmup; if bad enough it could act like you describe, I think. Do you see any soot in any of the injector holes? FWIW I also had similar symptoms in my 2002 ALH when it was getting air bubbles in the fuel, even *any* visible bubbles are bad. It turned out to be a micro-crack in the thermostatic T. A new one resolved it. Oldpoopie diagnosed and fixed it.
 
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