Rough idle 2.0 tdi white smoke

I'm having some problems with a 2.0 tdi 170hp at the moment, it's a PD engine, and to take things to the next level of difficulty, it's a 16v.

Started by a quick check of channel 13, noticed that cyl #1 was showing negative values below -4mg/str, and cyl #4 very high, above +4mg/str.

Anyway, noticed fuel a bit dark, suspected injector seals. Pulled the 4 injectores, and installed them in differente places. injector #1 to the cyl #2, injector #4 to cyl #3, basically moved the injectors #1 and #4 to the middle. New injector seals, new stretch bolts, 3nm+270°, injector lash set to 180°.
And I'm still getting the same result.

-4.08 1.02 1.85 1.21
-1.65 0.91 0.44 0.29
-3.55 0.74 2.18 0.61
-1.68 0.62 0.42 0.64
-4.04 1.52 2.18 0.32
-0.82 0.06 -0.06 0.82
-4.12 1.51 1.44 1.15
-3.97 1.95 -0.05 2.07
-4.12 1.56 -1.56 4.12



Cyl#1 is still cutting too much fuel, I assume that is neither injectors or seals, wiring loom is ok since i'm not getting dtcs.

Torsion value is at 1.04° and I can insert both locking pins on both cams.

Any advise where to look before start pulling of cams, lifters and head?

i dont know why your considering all that work at this point. to be truthful im not in the above mk4 knowledge area, and dont really know too much about pd.
but to suggest. 2 or 3 things to start. first a compression test, second a leak-down test, will determine how well your cylinders and the bottom end are doing. for us the last test for the bottom end is an oil pressure test. hook up a manual oil gauge and take a reading warm @idle. other than that look at the top end. injectors and operation is the most likely area to solve.

by the way, white smoke is one of a few things, usually 2.
1 timing is off, very advanced i think, to make white smoke more white smoke more far advanced. probably not this. 2 injectors, and or pd operation. new nozzles, or get a pro to clean out nozzles, that is if nozzles can be resurrected, another change fuel filter. purge can help prevent this, from time to time.

Thanks for your reply.

I really doubt its injector related, since I swapped all the injectors around and the deviations are on the same cylinder.

About the timing, I have a torsion value of 1.04, although thats the comparison between crank and cam sensor, just one of the 2 cams. I'm going to check the rear cam also, and since I'm at it, retard a bit the intake cam.

so where is your injection timing at? the advance timing i brought up in my post will be associated with injection timing. im not really sure of cam timing, for mine (a mk3) we just set the crank and cam to TDC.
im not really sure, but even with all your balances reading the same after something like an injector swap, id still be inclined to look into injectors. for one its white smoke. one of the main indicators is droplets of fuel being injected, not vaporized.

iluvmydiesels said:

so where is your injection timing at? the advance timing i brought up in my post will be associated with injection timing. im not really sure of cam timing, for mine (a mk3) we just set the crank and cam to TDC.
im not really sure, but even with all your balances reading the same after something like an injector swap, id still be inclined to look into injectors. for one its white smoke. one of the main indicators is droplets of fuel being injected, not vaporized.

Click to expand...

Your mk3 has a ve pump, and has it's own timing. On my PD, the timing is set with the exhaust camshaft, the exhaust camshaft operates the injectors.

Timing is perfect, still improved it to 0.7°, both locking pins insertable on both cams as before, still the same.

Yesterday got the M8x1.0mm adapter for my compression tester. Tested it. No compression at all on cylinder #2, completely dead. 430 psi on #1, #3 and #4.

Going to leak down test before pulling the head to figure out where is the loss of compression, even though I'm pretty confident the problem will be easy to find when the head comes off.

To end the chapter, has I was suspecting:

Yeouch!
How does the piston/cylinder that you moved that injector to look?

flee said:

Yeouch!
How does the piston/cylinder that you moved that injector to look?

Click to expand...

Where the #2 injector is at the moment, cyl #1, it's fine, but the car only idle a couple of minutes for diagnostics after the injector swap, wouldn't have time to wreck another piston.

350kkms compression ring with less than 0.4mm of gap, compression ok on the rest of the cylinders. Protrusion equal, ready for honing, a piston, 4 sets of rings and rod bearings.

But before I need to test that injector.