Should I adjust injection timing?

I used VCDS to check my injection timing. It was barely inside, at the top of the "allowable" range. Right by the green line.
My car starts immediately. Don't know about cold months. Absolutely no smoke on start up, but still suffering from low power.

Would it be a good idea to push injection timing back to the blue line? Would it benefit me anything? Hurt anything?


Is the blue line truly ideal or a soft recommendation?

Also, I noticed my oil cap somehow has a hole rubbed through it. Going to order a new one ASAP, but would this have any consequences on the motor?

If you read more here you will see that the 'top by the green line' is often the
recommended setting. Your low power is due to something else. Limp mode?
The crankcase is usually under pressure so an oily mess is probably the only
result of a hole in the oil cap.

Better starting and generally marginally better fuel mileage advanced as is. Won't be the cause of your low power situation. Test the MAF, test the turbo actuator for free full range movement, look for vacuum line leaks and check for intake manifold clogging. Even as simple as a clogged up fuel filter
There is a "sticky" list for checking out low power issues here somewhere.

I adjusted it. I checked the timing again, and it was actually a hair above the green line this time. Not sure if belt stretched, or variables (such as coolant temp, fuel temp, or other) took effect.

It's very sensitive. Moving the wrench barely a hair caused a lot of movement on the graph.
I'm now between "dead on" and "slightly retarded". No noticeable difference as far as I can tell.

I tried to find info about ideal setting, but it was a bit vague. But if 'green is the new blue' then it seems my motor was timed perfectly before I touched it. Although having it on the blue, which makes VCDS happy, I'm now conflicted if I should change it back. Are you saying Ross Tech is off the market in the true ideal timing range?

Also, I've tried just about everything regarding my low power and running out of ideas. Replaced MAF with new Bosch unit. No change. Got a junkyard Bosch TDI unit - same. Swapped N75 with N18, and both solenoids from JY car. No change. Replaced all vacuum lines. No change. Measured vacuum at idle, and used MityVac to open and close actuator 15-20 times while spraying WD-40 to help possible sticking. Replaced fuel filter. Zero change. Cleaned EGR and I/M of goop. Zero change. Replaced PCV and pipe.
I've thoroughly examined the plastic pipe going to turbo and the MAF bellows for leaks/cracks. And done a superficial examination of the IC and pancake pipe.

I haven't dug into the turbo at all, but I supposed I'm going to have to.

Moving the timing a bit won't have much of any impact in "power" changes.
VCDS shows VW "recommended spec" which was/is somewhat retarded for reduced NOX emissions mostly IIRC. Almost all "tunes" advance timing, I'm sure.
Years ago I adjusted timing quite a bit and logged all my fuel mileage (still do). Advanced resulted in a better mileage result. I even used adaptation to allow further advance. But, over the years of late I haven't messed with it much and leave it anywhere above the mid-line. I have never had it "move" any noticeable amount over the course of a TB change interval.
You say you have cleaned out the EGR of "goop". If the EGR was messy the downstream intake manifold and cylinder head intake ports to the valves will be constricted worse and will be more of an issue than the EGR. Unfortunately there is only one way to find out if it's a cause.

flee said:

If you read more here you will see that the 'top by the green line' is often the
recommended setting. Your low power is due to something else. Limp mode?
The crankcase is usually under pressure so an oily mess is probably the only
result of a hole in the oil cap.

Click to expand...

jettawreck said:

Better starting and generally marginally better fuel mileage advanced as is. Won't be the cause of your low power situation. Test the MAF, test the turbo actuator for free full range movement, look for vacuum line leaks and check for intake manifold clogging. Even as simple as a clogged up fuel filter
There is a "sticky" list for checking out low power issues here somewhere.

Click to expand...

jettawreck said:

Moving the timing a bit won't have much of any impact in "power" changes.
VCDS shows VW "recommended spec" which was/is somewhat retarded for reduced NOX emissions mostly IIRC. Almost all "tunes" advance timing, I'm sure.
Years ago I adjusted timing quite a bit and logged all my fuel mileage (still do). Advanced resulted in a better mileage result. I even used adaptation to allow further advance. But, over the years of late I haven't messed with it much and leave it anywhere above the mid-line. I have never had it "move" any noticeable amount over the course of a TB change interval.
You say you have cleaned out the EGR of "goop". If the EGR was messy the downstream intake manifold and cylinder head intake ports to the valves will be constricted worse and will be more of an issue than the EGR. Unfortunately there is only one way to find out if it's a cause.

Click to expand...

I cleaned EGR and the intake manifold.
The I/M had a very slight build up on the walls. Maybe a 8-10% restriction, but not enough to make any sort of airflow difference. I also used a mirror to inspect the intake ports on the head. Couldn't see anything other than them being black and moist from minor goop deposits. I used a scape tool on all 4 and couldn't get anything out. So I'm done and moving on from clogged EGR/IM/intake ports.

Check the check valve on vacuum line

Use the MityVac to measure the vacuum at the N75. It should be in the mid-20s "Hg.
If it's less than that check the pump outlet and booster hose, etc. for leaks.

bbexotics said:

Check the check valve on vacuum line

Click to expand...

I tested it about 6 months ago. It checked out! lol.
Will check again. Thanks

flee said:

Use the MityVac to measure the vacuum at the N75. It should be in the mid-20s "Hg.
If it's less than that check the pump outlet and booster hose, etc. for leaks.

Click to expand...

Is that the single hose on the right of the valve?

stomachbuzz said:

I tested it about 6 months ago. It checked out! lol.
Will check again. Thanks
Is that the single hose on the right of the valve?

Click to expand...

It's the hose from the vacuum pump.
Everything from the pump onward should be checked for leaks if the value is low.