Another rough poor starting problem 1.9 tdi awx

[Crispy87]

Hello everyone!
In my case there are problems with poor starting. When the ambient temperature is under -5, then it is hard to start the engine. I know, that there can be a lot of reasons, but glowplugs are ok and all other necessary things and conditions looks good . I have observe that if I briefly push the accelerator pedal(just gentle push on it) when starting, the problem of rough starting dissapear,therefore I think there are not enough fuel for easy starting for an engine.I am searching for way have to regulate the quantity of starting dosage of the fuel.I know that, for non- pd engines it is possible to regulate it with vag com.Is it possible to regulate it on this engine.Maybe there are some other reasons for such problem.
Thank you for an answer!

[Doctle Odd]

Coolant temperature sensor

[Crispy87]

I have cheked the coolant temp. sensor with vag-com, it looked fine. I woke up in the morning when there was -7 C shown on termometer behind window, and the vag com shown coolant temp -5,4 C, so i think there are no problems with it, in fact ,they are not a kind of laboratory measurment devices,and the tolerance in some difference + -2 degrees could be accepted. Maybe some other ideas. For example, today there was -6 degress C when I started the car.Waited for the glowplug light turns of, I didnt pushed the accelerator in that moment,the engine hit one time and then stops after some starter turnings, and then after another revs it starts fine, and very often there are some beep sound heard after such starting.When the engine is warm,there are no problems with it.I think the normal could be that the engine starts normally after some 1-2 sec, turning the starter when temp is -6 degrees.But mine first one or two times hits then nothing happens and then starts fine.This engine starting time can be reduced when i push the accelerator,then the engine starts without no misfirings.

[Columbusracing]

When it starts does it puff any white smoke from the tailpipe?

[Crispy87]

When it starts does it puff any white smoke from the tailpipe?

It could be so, in cases when I need to start engine for longer time.what could be the reason?But when the engine have worked for som minutes, then there are white smoke coming ,i thought it is an warmed up condensate water , and nothing bad at all,after a longer period of working the white smoke dissapears.

[Doctle Odd]

What fault codes were listed when it was scanned?

[Crispy87]

What fault codes were listed when it was scanned?

the most interesting was that,there were no fault codes at all.Using my car for 3 years, I haven't experienced any fault code in engine control module. But when the cold weather comes ,the problems with engine starting also comes again. But when I push an accelerator a bit, it starts normaly, after 1-2 sec starting without any hesitation.

[arman123]

when was the last time you changed the cars battery?

[Doctle Odd]

You should scan the whole car with VCDS instead of individual modules. It may be intermittent fault with the TPS

[Crispy87]

The battery was changed in 2011 october. I checked th system with Vag- com 409.1, i dont have full version of new VCDS.What is TPS?

[Doctle Odd]

TPS is throttle position sensor. You can download VCDS lite it should work with your cable (it's free)
The battery was changed in 2011 october. I checked th system with Vag- com 409.1, i dont have full version of new VCDS.What is TPS?

[A4flyer]

Hi crispy,

check out the other threads under starting problems on first page. Im having very same problem.Try filling the tank or even half filling and see if that makes a difference to your starting problems on those cold mornings.If it does you may have the same prob as I have ie a fuel leak in the vacuum HP pump.I only found out through the process of eliminating many other items such as glow plugs,air sensor and thermostat....check for any fuel leaks under the hood or any wet areas around the pump area.

[Crispy87]

Yes, there is leakage somewhere nearby the pump. I saw it, when I was repairing vacuum hose connection to vacuum side of tandempump with silicon grease, and there was some signs of a fuel leakage, but i thought it is still acceptable for driving, and I took it like a warning that soon something will go wrong with it. So , could it be the reason of such rough starting?Ok, I will pay attention on it more. Thank you.any way sorry for my bad english.I haven'y use it for a long time.

[Columbusracing]

It could be so, in cases when I need to start engine for longer time.what could be the reason?But when the engine have worked for som minutes, then there are white smoke coming ,i thought it is an warmed up condensate water , and nothing bad at all,after a longer period of working the white smoke dissapears.

White smoke is usually air getting into the diesel or water in the combustiona areas, areas that might be worth looking at are low pressure fuel pump, fuel filter and associated piping. If you go to a garage at any point get the block tested (test a sample of coolant) to rule out water gettting into combustion chambers.

Arman123 might be onto something do you have a multimeter to check the battery with? Should be above 12.6 before starting and should not dip below 10 when cranking. Vw's etc are very sensitive to battery voltage.

Doctor odd is reffering to the throttle position sensor (tps) which should be monitored by the engine control module as its only purpose really is for load calcs in the engines management.

[Columbusracing]

Yes, there is leakage somewhere nearby the pump. I saw it, when I was repairing vacuum hose connection to vacuum side of tandempump with silicon grease, and there was some signs of a fuel leakage, but i thought it is still acceptable for driving, and I took it like a warning that soon something will go wrong with it. So , could it be the reason of such rough starting?Ok, I will pay attention on it more. Thank you.any way sorry for my bad english.I haven'y use it for a long time.
If you have a fuel leak then that will be causing your problem lucky this has a low pressure pump to prime the high pressure or you would have major starting issues get that leak sorted before checking anything else :)

[A4flyer]

There seems to be a problem with tdi pumps from day 1. Later models were later recalled and pumps changed with a modified version. I have ordered a new pump today and it seems to have the additional metal gasket added. I have heard that it is possible to buy the metal gasket on it's own which can be fitted to your old pump but don't know how true this is.
Will call vw to confirm this. The inner working of the pump could still be a problem so I guess it's a chance you got to take. It could be a false economy trying to fix these things and then down the road end up having to take it all apart again.

[A4flyer]

http://forums.tdiclub.com/showthread.php?t=158519&page=3

Leaking Fuel Pump - PD. - TDIClub Forums (http://forums.tdiclub.com/showthread.php?t=158519)

Hope these links help shed some light.....

[pauldazzle]

I have cheked the coolant temp. sensor with vag-com, it looked fine. I woke up in the morning when there was -7 C shown on termometer behind window, and the vag com shown coolant temp -5,4 C, so i think there are no problems with it, in fact ,they are not a kind of laboratory measurment devices,and the tolerance in some difference + -2 degrees could be accepted. Maybe some other ideas. For example, today there was -6 degress C when I started the car.Waited for the glowplug light turns of, I didnt pushed the accelerator in that moment,the engine hit one time and then stops after some starter turnings, and then after another revs it starts fine, and very often there are some beep sound heard after such starting.When the engine is warm,there are no problems with it.I think the normal could be that the engine starts normally after some 1-2 sec, turning the starter when temp is -6 degrees.But mine first one or two times hits then nothing happens and then starts fine.This engine starting time can be reduced when i push the accelerator,then the engine starts without no misfirings.

Sounds like you are using the ambient/outside temp to reference whether the CTS is functioning correctly. You need to get the engine upto normal operating temp then check the engine temp the ECU is getting on VCDS/Vagcom. The CTS has 2 outputs one to the temp gauge the other to the ECU. If the ECU is getting incorrect reading it won't fuel correctly. Also the Starter motor has to achieve a minimum speed of 250rpm IIRC or the engine will not fire up.

[Crispy87]

Many thanks for all posts and explanations for everyone , I appreciate that.I m looking forward to repair my car on holidays if I get my garage warm and cozy:). First, I will deal with tandem pump as I was told some posts upper.Since I rememeber the leakage what I saw when I was repairing its vacuum connection, I am almost sure, that the pump must be maintained fully, and I will hope that it will give me any achievments in this case.If not, then I will go step forward to another reason.Thank you again!:beerchug: