Retarded the Timing, too much Boost

The other day, I got a 00550 - Start of Injection Regulation 17-10 - Control Difference - Intermittent code. I decided to check my timing, and it was on the upper bound of advanced, just grazing the line. I bumped the IP down to dead on center, and took the car for a drive on the highway.

Oddly, the performance wasn't that much better, but the boost was probably double. I was getting around 12psi just half throttle up gradual hills.

I think my power issues are related to an old diesel filter, so I'm going to change that out and see if my power issues subside.

I also have an issue with that sensor that informs my ECU about excess boost. Currently, I've been driving under 12psi to make sure it doesn't put my ECU in limp mode. Does anyone know the part number for that sensor so I can replace it?

1st off, can you clarify something please
Stock boost is like 15psi. Your running double your normal boost at 12? So you only run normally 6psi? Your wording is a little confusing.
Why are you running so low on boost?
Its perfectly fine to run on the top end of the graph especially if you run a lower QA. I ran 17psi at 1.4IQ on the stock nozzles and turbo with the line at the top of the graph. Ran really good. Still got into the 44mpg average so imo it makes no difference.

Yeah, I was getting about 6psi at half throttle back with the timing at the top of the graph. Now with it on center, I get twice that.

Half throttle means nothing. What rpms? Also vcds cant display the timing graph unless the car is idle.
Sounds about right. As long as your not boost spiking!
It would be really helpful if you posted a vcds log

I changed the diesel filter and took the jetta for a decent drive. It was still really sluggish, and it tripped the check engine light again.

I plugged in the VCDS at home and checked the timing. It did say it was "too hot", but it showed to be within timing spec about midway through the advanced area. It shows to be "a little advanced" in the text-label at the bottom of the VCDS graph window.

It has the same 2 faults when I checked the codes.

2 Faults Found:
01117 - Generator Terminal DF Load Signal
27-00 - Implausible Signal
00550 - Start of Injection Regulation
17-10 - Control Difference - Intermittent
Readiness: N/A

I noticed that it has a strange ticking noise at higher RPM's.

It's a little odd that I timed this "dead on" and now it's halfway advanced. Maybe that's due to the "too hot" signal.

Yup, ECU adjusts the timing w.r.t. fuel temperature (because the fuel density changes with temperature)... which is why timing best visualized as a graph.

Also note that what you are seeing is the "static" timing... the timing the ECU uses to start the car. Once the car is running the ECU takes over the timing dynamically, and all bets are off, graph-wise.

This is why monkeying with the timing does very little in terms of power, economy, etc... once the car starts it ignores the user set timing.

The exception is if the static timing is so far off mechanically that the ECU can't physically adjust the timing thru its full range electronically. People that notice a difference in power after adjusting the timing... the static "what to use when starting the car" timing... have probably just brought the overall system back into a range that the ECU can control it fully when in dynamic mode.

vince waldon said:

yup, ecu adjusts the timing w.r.t. Fuel temperature (because the fuel density changes with temperature)... Which is why timing best visualized as a graph.

Also note that what you are seeing is the "static" timing... The timing the ecu uses to start the car. Once the car is running the ecu takes over the timing dynamically, and all bets are off, graph-wise.

This is why monkeying with the timing does very little in terms of power, economy, etc... Once the car starts it ignores the user set timing.

The exception is if the static timing is so far off mechanically that the ecu can't physically adjust the timing thru its full range electronically. People that notice a difference in power after adjusting the timing... The static "what to use when starting the car" timing... Have probably just brought the overall system back into a range that the ecu can control it fully when in dynamic mode.

Click to expand...

^^^^
this
see it way too often with re seal jobs and mark and pray belt jobs!

Vince Waldon said:

Yup, ECU adjusts the timing w.r.t. fuel temperature (because the fuel density changes with temperature)... which is why timing best visualized as a graph.

Also note that what you are seeing is the "static" timing... the timing the ECU uses to start the car. Once the car is running the ECU takes over the timing dynamically, and all bets are off, graph-wise.

This is why monkeying with the timing does very little in terms of power, economy, etc... once the car starts it ignores the user set timing.

The exception is if the static timing is so far off mechanically that the ECU can't physically adjust the timing thru its full range electronically. People that notice a difference in power after adjusting the timing... the static "what to use when starting the car" timing... have probably just brought the overall system back into a range that the ECU can control it fully when in dynamic mode.

Click to expand...

The bolded section is what I've always believed to be true...that it doesn't do much other than impact the way the car starts. After that the ECU just says I know more about this and I'm taking over...

Steve

You should run a log of actual versus requested fueling. You may find your IP is getting tired, and that's why you have low power. The initial fault code you found could be a symptom of a pump quantity adjustor not working correctly.

IndigoBlueWagon said:

You should run a log of actual versus requested fueling. You may find your IP is getting tired, and that's why you have low power. The initial fault code you found could be a symptom of a pump quantity adjustor not working correctly.

Click to expand...

^^^^^^^^

Data is good to have, especially when there are multiple possibilities.

IndigoBlueWagon said:

You should run a log of actual versus requested fueling. You may find your IP is getting tired, and that's why you have low power. The initial fault code you found could be a symptom of a pump quantity adjustor not working correctly.

Click to expand...

My IP and injectors are at 320000 miles. I'll see if I can get a log later this week.

I'm also getting that ticking noise louder at high RPMs

genscripter said:

I'm also getting that ticking noise louder at high RPMs

Click to expand...

What's your oil psi?

Mongler98 said:

What's your oil psi?

Click to expand...

I have no idea. Is there a way to check through VCDS?

Here's a video of my engine sound: https://www.youtube.com/watch?v=BPkgWQgHy18

Always hard to tell over the interwebs, but to me that sounds mechanical, as opposed to ignition. Something mechanically clacking on something else.

Might be worth a pulling the timing belt cover and valve cover and checking the cam timing (can't be read using VCDS), in case the sprocket has slipped.

Or a compression test. Or both.

Could also be exhaust manifold leak I suppose.

But again, just my ears listening on a laptop.

genscripter said:

Here's a video of my engine sound: https://www.youtube.com/watch?v=BPkgWQgHy18

Click to expand...

Sounds like a normal ALH/ AHU to me but to hear it from inside the cabin means it’s really strong

Only things that make that classic tapping clicking sound on ahu and ALH engines are
A: worn IP (least common)
B: worn head (guides and valves)
C: Cam followers (lifter) bore is worn past spec.
D: low oil PSI from a worn out oil pump or massive oil leak like a worn turbo.

#1st and cheapest way to rule out a few things is a digital oil PSI gauge installed on a braided AN fitting oil turbo feed line

2nd is to take off the QA (top of the IP "injection pump") and suck all the fuel out of the bottom and inspect the cam and head by rotating FROM THE CRANK ONLY with a good flashlight.

Anything more and you are doing a LOT of work, AKA taking the head off. It’s not uncommon in fact it’s usually the case at 300K area to see about 1mm or more of side to side play on the exhaust valves. That’s way past service limit. Rebuilding the head is the only option or replacement.

Start simple with an oil PSI gauge.
If oil is within spec at all ranges of temp, then move to the IP. The tapping from the IP is slack and worn areas on the head and cam with the springs making less pressure causing more force to make this tapping.

To me, it sounds EXACTLY like your head is worn down past its service life. This can be from running low oil psi from a failing turbo or worn out follower bores. Any of the things that take away from good oil pressure ends up killing the engine. Heck it could be from worn crank bearings (usually #3)

Point is, do some cheap investigation, if you can’t sort it out, and run it till it dies (probably a 100K more “who knows”
Or throw your wallet at it!

the sound isn't there when the engine is cold. I would expect a worn head or other parts to have the same sound regardless of the temp of the engine.

Metal expands as it gets warmer, so tolerances of things that are going to hit each other get closer, and tolerances of things that are going to get looser get looser.

And again...just a theory.

Mongler98 said:

#1st and cheapest way to rule out a few things is a digital oil PSI gauge installed on a braided AN fitting oil turbo feed line

Click to expand...

A long time ago, my friend had a Passat TDI and we had the turbo feed line crack on a roadtrip. IIRC, it had a banjo fitting at the end, and it was hard to find in the parts stores at the time. I'm always cautious around that line, because I wouldn't want to break it.

My bentley manual doesn't have an exploded diagram of the 1.9 engine (just the gassers) so I'm going to assume the filterhead has two oil pressure switches similar to the gasser setup. Would it be possible to install a nipple on one of the switch ports and put a tee on it, to have the stock oil pressure switch and my oil pressure sensor on the other end of the tee?

I was reading some of the older TDIForum posts about gauges, and they were recommending an oil pressure gauge that goes between 80 to 100 psi. Just making sure that's still a good plan?

I think the after market oil feed lines (braided) are a -6AN fitting. The banjo for it comes with it. Get a -6AN fitting t with a 1/4 npt port on it and install after the banjo. It's how I did it.
Put your 1/4 npt fitting here for the pressure switch.

I ordered some parts and it'll take some time.

I wanted to explore some other things while I waited. I decided to run the jetta from a diesel can, just to make sure there isn't a fuel restriction somewhere from the tank to the filter. Some odd stuff happened. I connected a few 3/8" hoses to the supply inlet and return outlet of the diesel filter (I installed a new filter a few days ago), and put the hose ends in a jug of diesel. It started, but had no power. Nothing came out of the return hose. I took it for a spin, and that was a bad idea. It died just a few blocks from my house. I somehow got it home after it died 4 times.

It wouldn't even idle, and no fuel was coming out of the return hose. The IP wasn't pulling any fuel from the jug.

Just out of curiosity, I found an old e-pump in the garage and hooked it up to the supply line. Even though it was an old pump, it pulled fuel from the jug fine. I pulled the hose off the IP supply bib and used the e-pump to push any air out of the line into a jar. Then reconnected the hose and fired the jetta up. No problem. Idled fine and revved fine.

I hooked up a mityvac to the diesel supply hose and I was able to pull diesel from the line from the tank. Also, I blew into the return, and it wasn't obstructed. I reconnected the diesel supply hose and the return hoses to the filter, with the e-pump installed before the filterhead.

Now it drives better. More power and less shimmying. I still get the ticking noise at higher RPM's, but it doesn't feel like it's starving for power anymore.

Yea so you just proved your lift pump something in the tank or at the tan connection is the issue. I suggest pulling out the lift pump, replacing it and the check valves.

No lift pump in a '98 Jetta. Just a fuel level sender in the tank.

For some reason I though this was a 2001 mk4. My mistake.

They don't have lift pumps either. PDs starting in '04 have them.

IndigoBlueWagon said:

They don't have lift pumps either. PDs starting in '04 have them.

Click to expand...

I just ordered an N75 valve from you a few days ago. Since I'm in the engine bay, I figured I should replace the other things that are getting old or broken.

I'm still waiting for my oil pressure kit to test what I'm getting for psi. Shipping has been slow recently.