Raplacing an injector on TDI 105: high consumption ?

aelkaim

New member
Joined
Aug 2, 2022
Location
France
TDI
1.6 TDI 105
Hello
Lately, my engine failed on the highway. "security mode", the car would drive 20km/h, shaking eventually (running on 3 cylinders ?) and was finally towed. The day after it would restart perfectly, but the diagnosis (with computer) showed a problem with injector #2.
The mechanics offered to use an additive to clean the injectors. He tried, but it the end, said the values he could read with the computer didn't show a sufficient improvement for the injector #2. Injectors are all original ones, so 120.000km "old".
So we decided to order one refurbed injector from DieselNeussFix in Germany.
2 days after, it was installed. The mechanics said he performed a "0-reset" of all injectors, then introduced the value written on their head, via the computer.

After first start, I immediately noticed higher idle fuel flow: 0.8lph instead of 0,4-0,5 lph.
On the highway, consumption set around 6.5l/100 which is a good 1.5l/100 above I used to see. This was on a 400km trip.

At the end of the trip, I noticed major diesel smell, so I opened the cowl and it was a disaster: the fuel return line from the injector was unplugged with diesel everywhere... Well, I called the mechanics.

Obviously we have a problem with the fuel return line adapter which need fixing.
We also spoke about the consumption.
The mechanics said, "it's high because you have a leak". I'm unsure about that. I would say the fuel flow is calculated from what the injectors throw in the cylinder.
I asked we checked the injectors quantity deviation values with the computer.
The three old injectors are around 0. The new one is around -1,6. The mechanics says: "it's normal because it is new and the others are old". Well I don't know.

Please note that the engine is running good: good power, no smoke, no vibration, stable idle RPM. The mechanics noticed light clicking at idle which, he thinks, is related to the mismatch between injectors.

Last remark: after the 400km trip, when I shut down, I noticed fuel flow idle was back to 0,4-0,5lph. Is it possible that after injector replacement, there is a learning curve ?

I hope you can help and provide advice.

Thank you for your help

Kind regards
 

KKilo

Active member
Joined
Jun 6, 2022
Location
long beach ca
TDI
2012 VW Jetta sport wagon
You need to make sure the new injector is for that engine,
I see the same injectors on a 3.0 engines it works on 2.0 engines but they inject more fuel than the 2.0,
You need to change your glow plugs if they are collect some hard shield around and it makes your car miss fire, I had a similar issue I replace the injectors and I keep getting miss fire on cylinder 3, after cleaning my glow plugs it's been running smooth.
 

aelkaim

New member
Joined
Aug 2, 2022
Location
France
TDI
1.6 TDI 105
Many thanks for your answer.
the reference of the injector is the proper one, I double checked.
when you say about misfire I suppose you refer to the trouble I had on the highway. As I said, the diagnosis showed a problem with the injector 2 and the values that could be read were out of tolerance.
I will check the glow plug.

in your opinion, is it allowed to replace one injector only (when the other ones are 120k) or is it a bad practice ?
 

KKilo

Active member
Joined
Jun 6, 2022
Location
long beach ca
TDI
2012 VW Jetta sport wagon
You should cleaned all, it's not hard to remove them,

I put tener on a bucket just to cover the tips like 2 inches overnight it removed all black charcoal but the issuewas on the glow plugs, 120k is not many miles, did you ever change the fuel filter, if you did how was,
 

aelkaim

New member
Joined
Aug 2, 2022
Location
France
TDI
1.6 TDI 105
Hi,
Please apologize for the delay.
The fuel filter is replaced during each maintenance (so I think ?) and nothing particular was reported.
Here are the news:
- return lines have been replaced by new. No more leak
- consumption was still high
- I ordered a cable interface assy with VCDS
- I was able to perform an injector adaptation (learning minimum deviation). It worked. The result is: smoother idle, consumption at idle back to 0.3lph without AC

It's quite satisfying, though the replaced injector (by a refurbished one), shows a deviation quantity different from the others:

For memory, all 4 injectors had 120k km on them. The "new" one... I don't know.

Do you think those numbers are acceptable ?
The injector workshop accepts to refund the injector, and I could buy a new one eventually. Don't know if it would be better.

I hope you can advise. Thank you for your help.
 
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