TDI cold starting anything else to try

[BIGMIKE1]

Ok had my TDI 110 3 years now and every winter I have the same problem, it stutters with a cloud of white smoke when its cold starting in winter but once started runs perfect and easily does 60mpg regularly, so far I've fitted a new Bosch battery, new Bosch glow plugs and genuine Skoda CTS, I've checked I have power to the glow plugs so my next thought was pump timing but could this being slightly out cause a problem with really cold starts only and otherwise perfect running and good MPG???

Its just had the cambelt etc replaced at a VAG garage and they said they don't need to check the pump timing on VAG com as everything is locked/pinned when changing so should be right?

Just as back ground its a 2001 with full dealer history and 81,000miles so assuming it cant be anything major buts its just annoying me!

Mike

[pimpdriver]

New starter motor.

[yesiamtom]

The VAG garage sounds odd...I'm pretty sure the timing must be adjusted as the new cambelt may not be quite the same as the old one, I may be wrong though and I don't think my car was adjusted when the cambelt was changed 20k ago.

 

My car is on 121k, tdi 110 and does the same as yours. I get a small puff of whitish smoke when starting in the super cold. It's done this since I got it and drives perfectly fine. When it is very cold double cycling the glow plugs can help I find though, may be worth doing that! I think its just unburnt fuel, it certainly smells like fresh diesel.

[BIGMIKE1]

It cranks over fine and the engine fires straight away but it stutters and cuts out within a split second, then crank again and it fires instantly with a cloud of white smoke like you say stinks of unburnt diesel and then is running fine. It's always done it when really cold starting, sometimes it doesn't cut out just sounds like a split second misfire then sorts itself out, but figured it can't meant to be like that.

If the pump timing is slightly out can it just be adjusted on VAG com or does the pump itself need to be adjusted? I think a friend may have the full version so I'll see if I can have a look on there, but what am I looking for pump timing wise???

Mike

[pikpilot]

The VAG garage sounds odd...I'm pretty sure the timing must be adjusted as the new cambelt may not be quite the same as the old one, I may be wrong though and I don't think my car was adjusted when the cambelt was changed 20k ago.

 

My car is on 121k, tdi 110 and does the same as yours. I get a small puff of whitish smoke when starting in the super cold. It's done this since I got it and drives perfectly fine. When it is very cold double cycling the glow plugs can help I find though, may be worth doing that! I think its just unburnt fuel, it certainly smells like fresh diesel.

Mine has been exactly the same (mileage 83000). It was ok the first winter (2007/8) and in fact started easiest when the temp was well below freezing. The following winters it was as described by you two with unburnt fuel coming out and a suspicion that it was initially starting on just three cylinders. I then got the timing checked and it was moved to be more retarded. This made an improvement but not a cure. The following winters it gave diesel smelling smoke as soon as it fired. 

 

This year things are much better and so far no white smoke and instant starts. The only difference is that the timing belt has been changed again.

Looking back I can see that changes in the way it starts have always followed timing belt changes. Even at its worst it has always started after the second attempt and runs smoothly within a couple of seconds. The glow pugs were checked (and one changed) and the current being taken by each plug is correct.

My conclusion is that cold starting problems are related to pump timing. Belt changes have always been done by a respected main dealer but I wonder if the belt is simply replaced and timing not actually checked using their computer software. Perhaps this year it was checked and mechanically adjusted?

[rwbaldwin]

Take it to a garage that knows what they are doing. A garage is not a VAG specialist if it uses the 'lock & pray' method. Did they just replace the belt or did they replace the tensioner and pulleys too (full cambelt kit)?

[thesquiff]

I've had two 1.9TDIs 110s and both have done it a bit from time to time. I don't think it is anything to worry about. Mine seems to do it less if I park it uphill rather than downhill (drive is on a slope)? 

[yesiamtom]

Diesels can be a bugger to start when its cold, I just put it down to that.

 

Whether thats a wise choice or not : ) ? 

[KenONeill]

Well, the specialist I use explicitly say that they adjust the fuel timing as part of a cambelt change (they also automatically change the water pump), and it makes a measurable difference to fuel economy.

 

So I'd be highly suspicious of anyone who claimed that you don't need to check the pump timing.

[yesiamtom]

Do you require full VCDS/Vagcom to adjust pump timing or can it be done with lite?

 

I remember seeing a few years ago how to do it but have completely forgotten.

[whitep]

timing?

[BIGMIKE1]

They changed the full kit cambelt, waterpump, tensioner, etc and I specifically asked them about whether they needed to check the pump timing afterwards and was told if its locked up properly there's no reason too.

They did have good reviews online but so far I've found one engine cover nut missing, the cam cover breather not connected back to the air intake pipe and now my starting problems seems to be slightly worse than its ever been, so I'm wondering it my timing has always been slightly out and now its a bit more out or if I just think its a bit worse as haven't really had a problem till the weather has got cold again.

 

Can anybody confirm or deny if its possible for the pump timing to be far enough out to give a cold start problem but still run fine and get excellent MPG or would something else be noticeable just so I know if I'm barking up the wrong tree.

[whitep]

My timing on my octy 110 ASV was out far enough to have cold start problems, but I am running on WVO which requires advanced timing anyway. However I found my timing too far retarded even for diesel, and advanced it and it was a million times better. The timing should always be checked after a cambelt IMHO. There is a reason the pump has adjustment.

[Kandy]

I checked/adjusted the timing on my brother's 110 and it takes a tiny fraction of movement to go from off the scale under, to off the scale over.

Even with locking, there is no way (other than sheer luck) it would be right after a cambelt change.

It should also be checked periodically as the belt etc. stretch/wear.

[cheshire_cat]

I have a notion about the temp sender inside the pump which I think alters timing  -it's under triangular? screws and there should be a repair kit if it's faulty    should be checkable with vag com   needs some research ---seems like long ago   

[BIGMIKE1]

Been back to the VAG specialist and basically they seem to disagree with everything I've read and been told, they say wrong pump timing usually only causes hot start problems not cold and you can't really adjust the pump timing its just locked in place. From what I saw they stuck a Snap on code reader on so I don't think they even have VAG com to adjust the timing anyway, they reckon they would need to take it apart to recheck the timing.

 

Can anybody tell me how to check and adjust the pump timing on VAG com as a friend can get me the full version but he doesn't know a lot about it really???

Mike

[yesiamtom]

I guess it goes without saying you don't want to spend anymore money there then.

[trundlenut]

Been back to the VAG specialist and basically they seem to disagree with everything I've read and been told, they say wrong pump timing usually only causes hot start problems not cold and you can't really adjust the pump timing its just locked in place. From what I saw they stuck a Snap on code reader on so I don't think they even have VAG com to adjust the timing anyway, they reckon they would need to take it apart to recheck the timing.

Can anybody tell me how to check and adjust the pump timing on VAG com as a friend can get me the full version but he doesn't know a lot about it really???

Mike

They don't seem like specialists. I know you can get cold start problems when the timing is out.

In VCDS there is a specific program which displays a graph of the timing. There is a how to on the Ross tech site.

The engine needs to be up to temperature before you can check the timing.

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[BIGMIKE1]

Perfect thanks just had a look on that site and there's even a video demonstrating how to adjust the timing.

And no I don't think I'll be spending anymore money there!

Mike

[trundlenut]

Perfect thanks just had a look on that site and there's even a video demonstrating how to adjust the timing.

And no I don't think I'll be spending anymore money there!

Mike

What looks like a tiny movement of the pump can make a big difference to the timing. As long as you aren't right at one end of the slots on the pulley you should be OK.

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[KenONeill]

Been back to the VAG specialist and basically they seem to disagree with everything I've read and been told, they say wrong pump timing usually only causes hot start problems not cold and you can't really adjust the pump timing its just locked in place. From what I saw they stuck a Snap on code reader on so I don't think they even have VAG com to adjust the timing anyway, they reckon they would need to take it apart to recheck the timing.

 

Can anybody tell me how to check and adjust the pump timing on VAG com as a friend can get me the full version but he doesn't know a lot about it really???

Mike

Well, IMO if they don't have VCDS, they're not a VAG specialist. 

[BIGMIKE1]

Not had a lot of time recently but the cold starting has been absolutely terrible the last few weeks, so eventually I got VAGcom on it today and the pump timing was so far retarded it wasn't even showing on the graph! So much for there if its pinned in place its fine approach, anyway I've reset it to almost bang on the centre line so I'll just have to wait for my next cold start and fingers crossed that will cure it then I will be contacting said VAG specialist to see what they have to say. If anybody wants me to PM the garage in Manchester that it was then let me know as I'm not sure about the name and shame rules here.

Cheers again for all the help

Mike

[trundlenut]

Result. I would advance the timing a bit more so it is close to the upper line.

Name and shame the garage, it shouldn't be a problem.

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[BIGMIKE1]

Cold start this morning at 3 degrees outside temp and it was back to how I remember it being last winter possibly even slightly better if anything as I didn't notice the cloud of white smoke but will probably be a few more cold starts before I can tell for definite if its now the best its ever been.

 

What difference would advancing the timing closer to the upper line make???

Mike

[trundlenut]

It will help over time as the timing does seem to become retarded over time.

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