Engine Stalls After Starting: Troubleshooting Guide

Hello everyone,

For about 3 weeks now, my car (Skoda Octavia 4x4) with a 74kW TDI-PD engine has been occasionally making a strange noise when starting.

Tritt nur bei warmem Motor auf, meist wenn er für ein paar Minuten aus war. Ich gehöre zu denen, die den Anlasser nur sehr kurz bedienen. Bislang lief das Motörchen sofort, wenn ich den Anlasser nur ca. knapp 2 Sekunden betägtigte. Neuerdings tuckert er gelegentlich mehr oder weniger lang (max 5 Sekunden) mit einem etwas schäbbernden Geräusch, ähnlich wie wenn ein loser Auspufftopf klappert oder er bereits innere lose, abgerostete Teile hätte, vor sich her und geht dann aus. Dabei erreicht er auch nicht seine sonst übliche Leerlaufdrehzahl. Man könnte meinen, es würde etwas den Motor abwürgen. Ab und zu wiederholt sich das dann auch bei einem weiteren Starversuch. Halte ich den Zündschlüssel etwas länger tritt dieser Effekt nicht auf. Dieses Verhalten ist erst aufgetreten, seitdem ich ihn eben vor 3 Wochen mehrmals mit eingeschalteter Klima angelassen hatte. Zuerst dachte ich, es läge daran, daß der Anlasser den Kompressor mit durchdrehen müßte und der Motor nicht die notwendige Mindestdrehzahl erreicht. So hatte ich die Klima dann immer vorher abgeschaltet, aber das hatte keine Auswirkung auf das Problem. AnsOtherwise, the engine is running normally.

It would certainly be disastrous if the electric coupling of the compressor were to occasionally cause the compressor to start up unexpectedly.

'Does anyone have a tip?'



Regards,
Irish beer.

Hi,

You don't need to worry about the air conditioning when starting the engine, as the engine control unit (ECU) automatically turns it off for 30 seconds during startup.
PD engines require a camshaft position sensor to achieve a fast start-up process. If the sensor is misaligned or loose, the engine will start poorly.

I have another question after a long time. Where can I find the camshaft position sensor on the ATD engine? Does anyone have a diagram or overview that would help me quickly locate all the sensors? I removed the cover from the engine block and looked around the area near the valve cover, but unfortunately, I didn't find anything that looks like it could be the sensor.

irisches-bier wrote:

I still have a question about this, after a long time. Where can I find the camshaft position sensor on the ATD engine

?
Remove the cover of the Northwest wheel well (passenger side).
Located on the outside of the northwest gear, at the front and bottom, is the sensor, which is passed by the seven metal "tongues" of the gear.

The only cable connection in the area of the NW wheel also leads to the NW sensor .

'I was looking for the cover a while ago and eventually found it. However, when I tried to remove it, a hose (plastic tube) was in the way. I didn't want to break anything, either on the cover or in the engine compartment, so I didn't proceed with the disassembly. Could it be that you have to remove the hose (plastic tube) before you can remove the cover?'

irisches-bier wrote:

Could it be that you have to remove the air hose (plastic tube) for this?

Why are you asking questions about such simple topics? You should be able to assess that pretty well yourself, just by being there and seeing it.

The pipe is only secured with one clamp at each end. Feel free to remove it if it makes the job easier.

PS: Please don't take this personally, but very simple questions are generally not well-received here.

Regards,
Guste.

The reason I asked this silly question is that I'm having trouble following the instructions of the designers. It seems like you have to disassemble one part to remove a cover, and then reassemble it to operate the engine in order to take measurements. That's one thing. The other thing is that you always want to do as little work as possible, and maybe there was a trick. Everyone knows how it is – you make a huge fuss taking something apart or out, and then someone comes along and says, 'Why are you making it so complicated?' So far, I've only worked on gasoline engines (and by 'working on,' I don't mean I've completely disassembled or removed entire engines, but things like cleaning and adjusting carburetors, replacing mufflers, dent removal, sunroof repair, etc.), and the engine compartment was a bit more spacious in those (Passat models from 1973, 1978, 1982, and 1986).

'Since I've already broken a few things while disassembling the interior trim on my Octavia due to a lack of information, I wanted to ask. Hopefully, you'll understand. I can only work on the side of the road, and I obviously want to avoid leaving as many car parts scattered around as possible.'