Fabia vRS (ASZ): Advice on Synchro/Torsen angle

[pyromorph]

My 2003 pre-face lift vrs is getting old and over the last couple of years I've been on a never ending fix/spend/fix cycle to resolve various issues.

 

I'm currently trying to resolve a black smoke, over-fuelling, and mpg loss (currently down by 15mpg.. running between 30 and 40mpg on runs that normally give me above 50) issue.

 

Not so long ago I replaced the cam belt and didn't check the timing. I'd like to rule out bad cam sensor/bad timing.

 

I've never done a "happy" synchro log via VCDS, so I would appreciate it if someone who has could tell me if the attached logs are good or if that 0.0 / -0.6 is a sign that either the sensor or the timing is wrong.

 

Thanks,

Phil.

 

2023-03-15 Synchro logs.xlsx

[KeithCheetham]

Unsure if reading this will be of any value, but used as a basis for belt change on my Mk1 and mk2 1.4 TDI Fabias. Cannot really cross reference values you have taken to data collected in article.  Someone will probably be along soon to clarify.

 Did the belt change correspond to the smoke and economy issues. Surprised at the oiliness of that pipe - diesel or engine oil? Is it boosting correctly, there must be a way of reading values in VCDS or use something like Torque App on a phone and a bluetooth ODB2 dongle.

PD-adjust-cam timing VCDS Idle-TDI.pdf

Edited 15 March, 2023 by KeithCheetham

[sepulchrave]

Unplug the MAF.

[KeithCheetham]

Bit more reading that may or may not be useful, or even applicable to your engine. Just noticed there is a section on VCDS boost pressure reading. As usual, any readings from ECU rely on valid data from sensors.

VCDS AND PD TDI ENGINE HEALTH CHECK.pdf

[pyromorph]

10 hours ago, sepulchrave said:

Unplug the MAF.

 

I did, and it was like flattening/turning off the boost. That said, the MAF I replaced a long time ago (12 years ish) with a New Bosch one.. so It could be on its way out or it might need a clean. I'll take a look at the weekend.

[pyromorph]

11 hours ago, KeithCheetham said:

Bit more reading that may or may not be useful, or even applicable to your engine. Just noticed there is a section on VCDS boost pressure reading. As usual, any readings from ECU rely on valid data from sensors.

VCDS AND PD TDI ENGINE HEALTH CHECK.pdf 478.32 kB · 0 downloads

 

Thanks for the info, very useful. The good graphs and descriptions are a very good reference. Thanks.

[Lofty]

As far as I know, the Torsion value you are seeing is about what a PD is supposed to have so I suspect there are issues elsewhere. Always worth ruling the cam timing out especially if you have not long done a belt change.

[Boyes]

On 15/03/2023 at 20:23, pyromorph said:

My 2003 pre-face lift vrs is getting old and over the last couple of years I've been on a never ending fix/spend/fix cycle to resolve various issues.

 

I'm currently trying to resolve a black smoke, over-fuelling, and mpg loss (currently down by 15mpg.. running between 30 and 40mpg on runs that normally give me above 50) issue.

 

Not so long ago I replaced the cam belt and didn't check the timing. I'd like to rule out bad cam sensor/bad timing.

 

I've never done a "happy" synchro log via VCDS, so I would appreciate it if someone who has could tell me if the attached logs are good or if that 0.0 / -0.6 is a sign that either the sensor or the timing is wrong.

 

Thanks,

Phil.

 

2023-03-15 Synchro logs.xlsx 144.88 kB · 4 downloads

 

Usually that would be fine for torsion value, have a read of darkside's little guide for PD's.

https://www.darksidedevelopments.co.uk/Blog/pd-engine-hardware-tweaks/

Have you logged the coolant temperature sensor, between that or the thermostat it will either run cold, or think it's running colder that it is?

 

The only other thing I could suggest is injector fouling.

 

I would be looking for blocking turbo veins or checking the injector deviation?

[pyromorph]

1 hour ago, Boyes said:

 

Usually that would be fine for torsion value, have a read of darkside's little guide for PD's.

https://www.darksidedevelopments.co.uk/Blog/pd-engine-hardware-tweaks/

Have you logged the coolant temperature sensor, between that or the thermostat it will either run cold, or think it's running colder that it is?

 

Thanks for the link, ironically I've had a reasonable amount of hardware for my other project car (MK5 Golf 4Motion) from Darkside, but never spotted that article.

 

Update: I've found that the massive smoke was caused by a boost leak from the lower intercooler hose that I replaced a few weeks back. It looks like the retaining clip had come out of it's "track" on the topside, but in the track on the bottom. The hose appears to try and blow itself out of the intercooler housing but only at the topside of the hose (only visible when looking at it from above). The bottom of the hose is retained correctly. I resolved the issue and then jubilee/cable tied it. It's not coming loose again.

 

I've cleaned my MAF.

 

Next step is checking the syncro timing.

 

 

[sepulchrave]

It sounds like you've fixed it already, if it's still thirsty then you should probably replace the MAF altogether since cleaning is rarely effective and twelve years is a ripe old age for one.

[Boyes]

On 20/03/2023 at 08:52, pyromorph said:

 

Thanks for the link, ironically I've had a reasonable amount of hardware for my other project car (MK5 Golf 4Motion) from Darkside, but never spotted that article.

 

Update: I've found that the massive smoke was caused by a boost leak from the lower intercooler hose that I replaced a few weeks back. It looks like the retaining clip had come out of it's "track" on the topside, but in the track on the bottom. The hose appears to try and blow itself out of the intercooler housing but only at the topside of the hose (only visible when looking at it from above). The bottom of the hose is retained correctly. I resolved the issue and then jubilee/cable tied it. It's not coming loose again.

 

I've cleaned my MAF.

 

Next step is checking the syncro timing.

 

 

Has the car been remapped at all? Most remaps swap from MAF to map for the smoke calculation so it would serve no real benefit investigating apart from monitoring air into the motor through vcds.

 

Just a thought.

[pyromorph]

On 24/03/2023 at 05:40, Boyes said:

Has the car been remapped at all? Most remaps swap from MAF to map for the smoke calculation

 

It's a "stock" map, but many years ago I adjusted the EGR map (driven by MAF) so it "disabled" the EGR. I left the EGR un-blanked.

 

Thanks,

Phil.

 

 

Edited 25 March, 2023 by pyromorph

[pyromorph]

Just an update on this issue for anyone coming back to this in the future..

 

None of the symptoms I've detailed in the earlier posts have anything to do with the synchro angle. Most are to do with boost leaks.

 

That said, some observations about adjusting the synchro angle. The value sat at 0 with a regular flickering to -0.6 and back. I decided to see if I can get it closer to 0 and found it's REALLY difficult to split that difference. After an hour messing with the adjustment on the cam/sprocket I ended up with values all over the place and at one point the car wouldn't start and took a while to get it back to where I started. I ended up with 0 flickering to +0.6 and back. With a 30cm 1/2" ratchet, if you feel the cam move then it's too much. I took to leaning on the ratchet and hoping I moved it.

 

If anyone attempts it I strongly advise checking out the youtube videos and making sure you put some reference marks on the cam bolt/sprockets, if I hadn't I'd be in serious trouble and would need to reset the timing (as you would with replacing the cam belt with locking tools).

 

Not sure if anyone else has managed to get the timing bang on. I suspect this is purely an exercise in "can it be done" rather than "is it worth it"

 

Thanks,

Phil.