PD150 start up smoke issue

[andrewjb]

Hi All,

Going to start a new thread but had previous old threads on here. Got a PD150 ARL Seat Leon.

Car smokes white for ages on start up and sounds rough, it drives fine and after a few minutes of driving the smoke goes away. previously checked the injectors using VCDS and cylinder 4 was showing +2.99 continuous. Car is using no oil.

I have now replaced injector wiring loom which didn't solve it, and also fitted a different injector today with new seals. Inital start up after fitting the new injector was as rough/smokey as ever but went for a 20 minute drive and it the smoke/roughness cleared like normal, checked injectors again and injector 4 sitting at +1.5 on idle, previously injector 4 would always sit at +2.99 so I thought we had solved it and the smoke was just excess fuel left from old injector.

Let the car cool down for about 6 hours (-1 here in the UK at moment) and started it again, smokey as hell and injector 4 showing +2.99 again! what could be causing injector 4 to be at +2.99 on startup, presume its flowing a lot of diesel hence the white smoke (smoke stinks).

Some kind of sensor? car previous had a missfire on cylinder 4 code but has no codes now, camshaft also looks good! it does this on OEM map or Stage 1 map. Car does also have a knackered DMF but fitting Valeo SMF soon once I can get this issue solved.

 

[STDOUBT]

using VCDS and cylinder 4 was showing +2.99 continuous.

That's the Injection Quantity for cyl. #4? What are the rest of the numbers!?

 

[andrewjb]

@STDOUBT

This was this morning cold start, lots of smoke again, temperature was +3.5 (Celsius, so 38.3F)

Cylinder 1 -1.06
Cylinder 2 -0.80
Cylinder 3 -1.39
Cylinder 4 +2.99

If I hold the revs at 1500 cylinder 4 goes down slowly and eventually sits like this

1 -1.86
2 +0.26
3 +0.68
4 +0.85

I'll take it for a drive in a bit but usually a 15-20 minute drive the smoke and running clears up nicely.

As said above its had a new injector loom and new seals on injector 4, plus injector 4 has been swapped for a different one.

 

[andrewjb]

Here's a video I took for the cold start.

I am holding the clutch in during the video as the DMF is noisy. The car has the N75 "deep idle" mod on ECU. Car doesn't use oil.

After a few minutes driving it idles lovely.

 

[tdi_my live]

you are sure that the injectors are original 550? There are two consumption indicators. When the car is idling, how many l / h (liters per hour) does it shows? 0.6-0.7 l / h in a warm state is ideal. And what is last value is in MWB04 (Timing) with idling?

 

[andrewjb]

Yes all original, the replacement one we fitted yesterday was from a BXE but same part number. all original nozzles etc.

 

[tdi_my live]

Thats not right. BXE have 073AG and ARL have 073AL Nozzles. They are different.

 

[andrewjb]

Ah yes just looked at the ARL we took out that does say 073AL on it, not sure on then one that's gone in.

So I have just checked a cold start again now, its now +7 degrees
1 -0.56
2 -0.09
3 -0.52
4 +2.99
Sync angle -1.65
Maf specified 850
maf actual 451

After 20 minute drive at idle
1 -1.36
2 -0.94
3 +0.54
4 +1.76
Sync angle still 1.65

I turned it off and started it again straight away, no smoke! but still 2.99
1. -1.48
2. -0.80
3. -0.85
4 +2.99


I'm starting to think maybe the smoke at cold is caused by injectors 1-3 leaking past seals as well (we have changed seals on 4) and actually the issue with smoke isn't caused by +2.99 on cylinder 4?

 

[tdi_my live]

These are the values of 13. What do the values of 23 say?
Is the turbo original or outdated? Was the stop screw turned on the VTG when it was closed? If the VTG is too far, the engine threatens to suffocate due to insufficient air. Signs, bad idle and white smoke.

 

[andrewjb]

I'll have a look at 23 now, Turbo is standard GT1749. The idle smooths out after a few minutes, its never suffocated just a bit lumpy.

 

[andrewjb]

Just been out to the car now, its been sat for 2 hours, engine cold, started it and no smoke and running smoothly, checked straight away injectors

1 -0.82
2 -0.89
3 -0.45
4 +2.16

23 has "no data" but I found 15 which has:
rpm 903
injection quality actual 5.76 mg/h
fuel consumption 0.60 l/h
injection quality requested (accelerator) 0.00 mg/h

 

[tdi_my live]

23 with no data is not normal
15 is all good

If the car ist cold and you pull the MAF off and start. What Happen?

 

[andrewjb]

just unplug the maf? will try in the morning when its nice and cold.

 

[andrewjb]

So finally got round to taking the other 3 injectors out today, fitted new seals to all 4 injectors now, also confirmed that the injector we fitted a few weeks ago is an ARL injector not BXE. So the car now has new seals on all injectors and also 4x new glowplugs. It also has a new injector loom.

So initial start up +2.99 on injector 4 again and then eventually after a few mins it settles at +1.60 to +1.69, the rest are

1 -0.64
2 -0.64
3 -0.42
4 +1.67

so whats next? camshaft? looks ok from inspections.

 

[andrewjb]

anybody got any thoughts? going to send a whole tank of diesel purge through the system.

 

[andrewjb]

Here's a video this morning, 9.5 degrees Celsius, as said above its had new injector seals and glowplugs, always starts but sometimes sounds like its going to stutter. After a few minutes smoke gets less and after few mins of driving it goes away.