Curious Chris
Top Post Dawg
Yes Full throttle is always the best test. When you are at 100% throttle a lot of adaptation disappears.
2011 Stage 2 TDI - Gutless, lots of boost, lower EGTs, quieter, no codes??
- Thread starter lindenladouceur
- Start date
lindenladouceur
Active member
Which question are you referring to exactly?
lindenladouceur
Active member
I'm reposting this question because I'm worried it will get lost on the end of the 2nd page. I apologize in advance but I am just extremely curious as to the cold/hot variations of this car. Thanks!
Hello all, quick update and yet another question:
I've put on about 3000 km since I left Squamish, the car still runs very poorly when cold (knocks, stumbles/hesitates), but appears to be running 100% once warmed up to operating temperature. I checked the fuel filter around 2000 km ago and there were more metal flecks.
Can someone help me understand why the car runs fine once warmed up? It is my understanding that small metal particles from the HPFP are getting into the injectors and causing misfueling which results in the knocking and hesitating, but why is this only the case when the car is cold? I just drove 10.5 hours back to Squamish and once I'm on the highway I forgot about how big of a POS this car is.
Hello all, quick update and yet another question:
I've put on about 3000 km since I left Squamish, the car still runs very poorly when cold (knocks, stumbles/hesitates), but appears to be running 100% once warmed up to operating temperature. I checked the fuel filter around 2000 km ago and there were more metal flecks.
Can someone help me understand why the car runs fine once warmed up? It is my understanding that small metal particles from the HPFP are getting into the injectors and causing misfueling which results in the knocking and hesitating, but why is this only the case when the car is cold? I just drove 10.5 hours back to Squamish and once I'm on the highway I forgot about how big of a POS this car is.
Because when you are working with compression ignition, a hot engine can handle poorly atomized fuel much better than a cold engine. Thats one possible reason for your possible problem.
740GLE
Top Post Dawg
- Joined
- Aug 19, 2009
- Location
- NH
- TDI
- 2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
that and doesn't the fueling system have a thermal switch in the fuel filter? or is that only on the older Olympic style filter and only active at colder temps than you're seeing?
Lots of parameters are modified when cold. Do you have and EGR delete or codding for EGR delete, but not blocked off?
Lots of parameters are modified when cold. Do you have and EGR delete or codding for EGR delete, but not blocked off?
lindenladouceur
Active member
Thanks for the potential explanation, that does make logical sense to me.
Not sure about the thermal switch in the fuel filter, the car usually cools down to 15 degrees C overnight, and then has issues every morning warming up.
EGR is turned off through tuning, the EGR canister was removed with the DPF, but the cooler and EGR valve are still on the car.