juddering and strange sound at cold engine. Injectors?

[Kjetil1Z]

I have a CFFB (2.0 TDI) that when on cold engine makes a strange rattle/tractor sound on medium throttle. Also when accelerating the car judders and feels like it have less power, as if it do not get enough fuel or something. This only happens when engine is cold, and only the first few accelerations.

 

The first that comes to my mind is injector(s). Am I on the right track you think?

 

I do have a genuine VAGCOM cable. Which parameters can I use to diagnose fuel delivery/injectors?

 

Thanks! 

[TasMan]

What sort of mileage (km) have you done ?  

Has the car been well serviced ?  I would have thought a general scan for faults would be the first option, see if it flags anything up rather than focusing on one particular problem.

Engine mounts have been mentioned on here in the past, could also be servicing related.

 

 

[Kjetil1Z]

The car has done 135.000 km. Oil change about every 15.000-20.000 km. I guess this would happen not only on cold engine if the engine mounts was the culprit?

I will do a general scan to see if anything shows.

 

 

[adoni546]

try to go to official Skoda store and check injector parameters there ! also check egr valve or dpf filter if it is clogged !?

[Kjetil1Z]

8 hours ago, adoni546 said:

try to go to official Skoda store and check injector parameters there ! also check egr valve or dpf filter if it is clogged !?

 

Have booked next week. I'll give an update afterwards :-)

[adoni546]

Idk if you have some shop that can disable egr and dpf filters. If you do, then ask them to remove or drill dpf filter . After disabling egr valve go and clean intake! 

[chimaera]

1 hour ago, adoni546 said:

Idk if you have some shop that can disable egr and dpf filters. If you do, then ask them to remove or drill dpf filter . After disabling egr valve go and clean intake! 

Unless you get a remap, it's a really bad idea to remove DPF and EGR. Even with a remap it's still not a great idea.

 

It's also very premature to suggest this course of action when it's not even certain that the problem is engine related.

[Kjetil1Z]

Had the car at the dealer today. Measuring injector quantity showed bad injector on cylinder no. 1.

Edited 22 September, 2020 by Kjetil1Z

[chimaera]

3 hours ago, Kjetil1Z said:

Had the car at the dealer today. Measuring injector quantity showed bad injector on cylinder no. 1.

Out of curiosity, did they say what the IQA deviation was?

[adoni546]

It is an awesome idea to disable egr and dpf filter. They don’t do anything good to the engine just clogging it up ! I have it done on my superb and even tuned car without it those filters  and car works like charm, I pass every eco test. So, it was up to injector. Well , try to find just one injector and measure again. Mine injecotrs were +0.1;+0.1; -0.1;-0.1

[Kjetil1Z]

On 22/09/2020 at 21:08, chimaera said:

Out of curiosity, did they say what the IQA deviation was?

 

unfortunately no. I was a bit in a hurry, so I did not ask either.

[Kjetil1Z]

On 23/09/2020 at 00:14, adoni546 said:

It is an awesome idea to disable egr and dpf filter. They don’t do anything good to the engine just clogging it up ! I have it done on my superb and even tuned car without it those filters  and car works like charm, I pass every eco test. So, it was up to injector. Well , try to find just one injector and measure again. Mine injecotrs were +0.1;+0.1; -0.1;-0.1

 

I may do it sometime soon. It may be that my insurance cover the injector failure. If not, I will just buy a new injector, and change it myself. It seems to be an easy job.

[chimaera]

Replacing the injector requires seals, clamp, and clamp bolt to be replaced and careful torquing of the clamp bolt.

[adoni546]

By replacing injector as @chimaera said, it’s not an easy job. Plus you need to replace seals on each injector. You have on ebay just type injector repair kit and go to someone who knows what to do! 

[chimaera]

2 hours ago, adoni546 said:

By replacing injector as @chimaera said, it’s not an easy job. Plus you need to replace seals on each injector. You have on ebay just type injector repair kit and go to someone who knows what to do! 

I didn't say it was difficult (it isn't really for a competent mechanic with the right tools) just that you need more than just a replacement injector to do this.

[Racataian]

What are the normal values of the injectors for a CFFB engine? At cold one of the injector got above 2mg/stroke. After the engine is warm they go bellow +/-1mg/stroke

At cold I have a bad noise