car stalled while driving - now works fine?

[Magnus Will]

2003 Jetta tdi stalled while driving - had driven it 14 miles into town, engine temp was reading 180 degrees or so, just approaching the on ramp to get on freeway when the engine stalled - got over to shoulder - tried to restart - engine turned over but wouldn't catch, after 3 attempts I lifted the hood and checked the fuel line- looked good - I got in and turned it over again - engine started and ran for about 4 seconds and stalled. I called a tow truck - they said they would be there in an hour. After 20 minutes I had a hunch the car might start - I turned it over and it started immediately - I cancelled tow and drove it to my son's house a few blocks away. I have tried starting it a few times over the last week and it starts and runs just fine. I'm afraid to try driving it back home as there's no shoulder on our river road for 12 miles. I haven't been able to find anything wrong that may have caused the stall. I recently removed and cleaned the EGR and inlet manifold. The turbo actuator was working so I did not clean it - I replaced all the vacuum lines at that time, also the air and fuel filters. I had done a few test drives and the turbo was working well (car had been in limp mode before I cleaned the inlet manifold). This was the first longer drive. I'm wondering if gunk from the turbo might have come through and caused the stall. I'm a total novice on this. Any ideas?

 

[JETaah]

Possible relay 109.
It powers a great deal of engine components and is a known sore spot if it is still the original component that came with the car. (black case VW OEM emblem) The updated VW part has a grey case.
The video will show you where it is located on the relay panel. A giveaway that it is not functioning is that they glow plug light will not illuminate (even momentarily) when you flip the key to 'on' position.

If it is the problem it is an important hard working part so don't buy too cheap. Dealer gets around 50 bucks for them and aftermarket is around 10-12 bucks.
1J0906381A

Relay 109 (A4)(B4)(A3)

Relay 109 is the main power supply relay for A3/B4, and A4 TDIs with the ALH engine. When it fails the engine will crank but not start. Sometimes they fail intermittently. Most TDI owners like to k...

www.idparts.com

I'm not at all a fan of Meyle parts of any kind but it looks like the choices are starting to narrow for these older cars.
Here is another choice - never heard of this brand

https://www.autohausaz.com/pn/1J0906381A

 

[csstevej]

Another thing that it could be is the crank shaft position sensor. They fail randomly and don’t always set a code.
This happened to me , car ran fine then one day I had trouble starting it. Once started had to keep the rpms over 1200 other wise it would die , but once warmed up it was fine even idled normally . When the car was cold same thing happened all over again , sometimes it just wouldn’t start.

 

[Magnus Will]

Thanks for your suggestion JETaah, I ordered that relay online. At that price it's worth getting - my jetta has a bit over 225,000 miles and I'm pretty sure this has never been replaced. And thanks also for the video. I'll let you know how it goes.

 

[Magnus Will]

Another thing that it could be is the crank shaft position sensor. They fail randomly and don’t always set a code.
This happened to me , car ran fine then one day I had trouble starting it. Once started had to keep the rpms over 1200 other wise it would die , but once warmed up it was fine even idled normally . When the car was cold same thing happened all over again , sometimes it just wouldn’t start.

Thanks man, I'll keep that one in mind. I'm thinking it's not that as the engine was not cold when it stalled and when I did get it to start, it idled and accelerated normally. Also I've started it cold a couple of times since.

 

[joyjoy22]

I am happy that you have managed to solve the problem. Cars with high mileage should be well-maintained to avoid other complications in the future.

 

[Magnus Will]

Another thing that it could be is the crank shaft position sensor. They fail randomly and don’t always set a code.
This happened to me , car ran fine then one day I had trouble starting it. Once started had to keep the rpms over 1200 other wise it would die , but once warmed up it was fine even idled normally . When the car was cold same thing happened all over again , sometimes it just wouldn’t start.

Possible relay 109.
It powers a great deal of engine components and is a known sore spot if it is still the original component that came with the car. (black case VW OEM emblem) The updated VW part has a grey case.
The video will show you where it is located on the relay panel. A giveaway that it is not functioning is that they glow plug light will not illuminate (even momentarily) when you flip the key to 'on' position.

If it is the problem it is an important hard working part so don't buy too cheap. Dealer gets around 50 bucks for them and aftermarket is around 10-12 bucks.
1J0906381A

Relay 109 (A4)(B4)(A3)

Relay 109 is the main power supply relay for A3/B4, and A4 TDIs with the ALH engine. When it fails the engine will crank but not start. Sometimes they fail intermittently. Most TDI owners like to k...

www.idparts.com

I'm not at all a fan of Meyle parts of any kind but it looks like the choices are starting to narrow for these older cars.
Here is another choice - never heard of this brand

https://www.autohausaz.com/pn/1J0906381A

I am happy that you have managed to solve the problem. Cars with high mileage should be well-maintained to avoid other complications in the future.

Howdy joyjoy22, I don't know that I have yet. I'm going to replace the relay 109 and see if that works. Thanks, I appreciate the advice from folks on this forum! I will post again when I know more.