3 issues to sort out

flashmayo

Veteran Member
Joined
Apr 1, 2007
Location
Santa Cruz CA
TDI
'03 Jetta - Gator Tuned
Pre-Diesel Purge:


Idle Stabilization (Injection Quantity deviation)
0.00 mg/str IQ Cylinder 1
0.07 mg/str IQ Cylinder 2
-0.47 mg/str IQ Cylinder 3
0.35 mg/str IQ Cylinder 4
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Those numbers are pretty good. #3 and 4 might be a bit out, but not terribly so. If you have worn injectors causing poor atomization (thus the smoke) it's likely across all of them and due to nozzle erosion, which does happen over time (the only fix is to have them checked, likely replaced, and then re-balanced.)
 

flashmayo

Veteran Member
Joined
Apr 1, 2007
Location
Santa Cruz CA
TDI
'03 Jetta - Gator Tuned
Post Diesel-Purge:


20:17:53 Group 013: I.Q. Idle Stabilization (Injection Quantity Deviation)
-0.45 mg/str IQ Cylinder 1
0.21 mg/str IQ Cylinder 2
-0.05 mg/str IQ Cylinder 3
0.26 mg/str IQ Cylinder 4



I ran .5 ltr. of diesel-purge using the bypass method. My bypass setup had an inline filter in the return line back to the jar with the diesel purge in it. the filter was as clean after running the purge as it was before. I still have a puff of smoke on startup, so that didn't fix anything.

I looked more carefully out the rear window as I started it up after sitting over night. There wasn't smoke immediately after the engine started, but there definitely was after a few rpms. I'd say 3 seconds max.
 

flashmayo

Veteran Member
Joined
Apr 1, 2007
Location
Santa Cruz CA
TDI
'03 Jetta - Gator Tuned
So, what are the next steps?

Grey smoke at startup only. Smells like fuel.
Diesel Purge treatment didn't change the smoke.

Runs pretty good, no stuttering, smooth acceleration, no dropoff in power.
This is a recent development, maybe 30-40K miles tops.
Is it time for nozzle replacement?
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Probably. Got anyone near you that can pattern-test (and pop test) those injectors? You need somewhat-specialized gear to do it correctly as these injectors are a two-phase design, although a simple pattern test might be enough if it's real obvious (odds are it probably is.)

Have you run a compression test? Low but even compression can be responsible for this too and would be worth eliminating.
 

BamaB4S

Veteran Member
Joined
Oct 28, 2011
Location
AL
TDI
1996 Passat
So, what are the next steps?

Grey smoke at startup only. Smells like fuel.
Diesel Purge treatment didn't change the smoke.

Runs pretty good, no stuttering, smooth acceleration, no dropoff in power.
This is a recent development, maybe 30-40K miles tops.
Is it time for nozzle replacement?
Many members use fuel additives to treat ULSD fuel. In my experience Howe's Diesel Treat eliminates, or minimizes, puffs of smoke at startup.
 

flashmayo

Veteran Member
Joined
Apr 1, 2007
Location
Santa Cruz CA
TDI
'03 Jetta - Gator Tuned
Belated update on this smoke issue. I tried playing with the injection timing with the VCDS. It was spot on the center line. I advanced the timing so the actual now sits between the middle line and the upper line. In the last 3 months I've noticed a puff of smoke only once or twice. Was this the fix? Don't think so. I also notice that I get about 45 mpg now where before changing the timing I got 46+ calculated every fillup. Still need to try moving the timing to below the middle line to see what that does.
 

flashmayo

Veteran Member
Joined
Apr 1, 2007
Location
Santa Cruz CA
TDI
'03 Jetta - Gator Tuned
Further update on this.
Using a HFT compression tool, cylinders read 480, 500, 500, 500. Those absolute numbers could be off, but the consistency rules out a leaking head gasket.
Still have a puff of smoke at startup, a very mild amount of black specks in the coolant bottle, and a very small loss of coolant. The coolant level drops by maybe a .25” over 5000 miles. No seeping at the heater core connections.
 
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