makita
Veteran Member
- Joined
- Aug 30, 2005
- Location
- Joliette
- TDI
- Jetta 1.9 TD 1992, Jetta Variant 1.9 TDI 2003, Golf Variant 1.8 TSI 2016
Need help to troubleshoot a rough idle on an ALH
The car:
Jetta Wagon 2003, bought in 2009 at 160 000 km, now at 454 000 km.
The maintenance is up to date, I'm the only one working on this car.
The engine is bone stock, no chips, original turbo, original injectors.
The only mod was to upgrade the ''Sachs'' DMF by a brand new ''LUK'' DMF, by prevention.
The background
At the end of last winter, I suddenly noticed that when cold, the engine was not idling as it used to. Instead of that nice tight 903 rpm idle, it was sounding as it was misfiring on one of the cylinders and the engine was shaking. However, as soon as I was pressing the accelerator (even a slight press), the engine was revving just fine.
The above symptoms were mysteriously disappearing as soon as the coolant would precisely reach 50°C. (temperature reading on VCDS)
There was no error code, the IQ was around 2.5-3.0, no air bubbles in the lines, timing belt tight and in place etc.
Since this was not causing any starting or drivability issues, I left the car this way and thought I should eventually change my nozzles as ''it might help''
The problem
This morning, outside temp at -10°, I started the car as every morning. It fired right away but stalled within seconds.
I gave it a second try and kept the key at ''start''. It fired right away, but stalled within seconds as before, even if the starter was cranking up. At this point, I opened the hood, the fuel lines were full and there was no bubble. (yes, the hoses were full of fuel, not full of air
).
I gave it a few other tries with all kinds of combination of starter and throttle without any luck. The exhaust was smoking and smelling unburnt fuel like an old D7 at -45°C, so fuel was definitely injected somehow.
After ~2-3 minutes of starting, the engine was finally able to keep running by itself, with an impressive quantity blue-grey smoke smelling unburnt fuel. At this point, it was impossible to rev it more than 1100-1200 rpm and the engine was sounding as there was too much advance.
I let the engine warm for few minutes (hoping the neighbors wouldn't call the fire department...) and when the coolant reached 50°C, everything went normal, the engine was idling 903 rpm as it was back in 2003, no smoke, no misfires, no lack of power etc.
Of course, there’s no stored code...
Anybody had seen something like this? Injectors? Needle lift sensor? N108?
The car:
Jetta Wagon 2003, bought in 2009 at 160 000 km, now at 454 000 km.
The maintenance is up to date, I'm the only one working on this car.
The engine is bone stock, no chips, original turbo, original injectors.
The only mod was to upgrade the ''Sachs'' DMF by a brand new ''LUK'' DMF, by prevention.
The background
At the end of last winter, I suddenly noticed that when cold, the engine was not idling as it used to. Instead of that nice tight 903 rpm idle, it was sounding as it was misfiring on one of the cylinders and the engine was shaking. However, as soon as I was pressing the accelerator (even a slight press), the engine was revving just fine.
The above symptoms were mysteriously disappearing as soon as the coolant would precisely reach 50°C. (temperature reading on VCDS)
There was no error code, the IQ was around 2.5-3.0, no air bubbles in the lines, timing belt tight and in place etc.
Since this was not causing any starting or drivability issues, I left the car this way and thought I should eventually change my nozzles as ''it might help''
The problem
This morning, outside temp at -10°, I started the car as every morning. It fired right away but stalled within seconds.
I gave it a second try and kept the key at ''start''. It fired right away, but stalled within seconds as before, even if the starter was cranking up. At this point, I opened the hood, the fuel lines were full and there was no bubble. (yes, the hoses were full of fuel, not full of air
). I gave it a few other tries with all kinds of combination of starter and throttle without any luck. The exhaust was smoking and smelling unburnt fuel like an old D7 at -45°C, so fuel was definitely injected somehow.
After ~2-3 minutes of starting, the engine was finally able to keep running by itself, with an impressive quantity blue-grey smoke smelling unburnt fuel. At this point, it was impossible to rev it more than 1100-1200 rpm and the engine was sounding as there was too much advance.
I let the engine warm for few minutes (hoping the neighbors wouldn't call the fire department...
) and when the coolant reached 50°C, everything went normal, the engine was idling 903 rpm as it was back in 2003, no smoke, no misfires, no lack of power etc. Of course, there’s no stored code...
Anybody had seen something like this? Injectors? Needle lift sensor? N108?
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