w176 1.5 diesel cold start problem

[Juky]

Hi!
i have a 2013 w176 with the Renault 1.5 diesel engine. i had problems with the cold start , when outside temp is below 10 Celsius, the colder it is, the hard for engine to start.
i had replaced both batteries
replace glow plugs + relay.
after this the starting it did improve a bit, but still the starter motor has to turn 3-4 seconds until starts , when below 5 Celsius, until the engine gets wormer i have bad injector knocking
i tested the injectors professionally and was told that all 4 are not working correct so i replace the injectors (bought second hand ones)
Temperature sensor is working ok
MAF sensor cleaned, works ok
Now i don`t have any errors on tester, after the engine gets warmer car is working perfect, pulls ok, no lagging, no smoke
Only problem is with the cold start,
i`m afraid that because of the knocking also the new injectors will fail
Anyone has any idea what else to try? what else to replace?

 

[mattkh]

Hi
How clean is the engine oil..??

 

[Juky]

Clean oil. Changed less than 2 k miles ago

 

[brandwooddixon]

Do you turn the key part way and wait for the glow plug light to go out before turning the engine over?
Were the "new" injectors refurbished?
Also when did you last fill the car with fuel?

 

[Juky]

The new injectors where tested before fitting.
I fill the car with fuel every 2-3 weeks.
Yes i turn the key and wait for 5-10 sec, i have try to do this 4-5 times before actualy start the car but is the same thing. I can hear the fuel pump working each time i turn the ignition on.

 

[mioba]

What code reader are you using. Not all the same.
What code was it showing.

 

[Juky]

i am using Launch CRP Touch Pro.
before i had codes for spark plugs and injectors. since i have change them i don`t have any codes . i had code for dpf regeneration in the past but i have force start the regeneration on long trip and now is ok.
i realy don`t know what else to try

 

[mattkh]

Hi
If the mileage is a lot, then I think the starter needs a clean.

 

[Juky]

Only 120k miles starter motor looks new, i think it was replaced not long time ago. I bought the car 3 months ago. When i bought the car in August because was warmer it didnt have any problems . As it gets coolder out side 5 Celsius-0 celsius the problems started

 

[mattkh]

How many minutes does the bad injector knocking stay on.
Is it possible to put up a recording of the sound..?

 

[brandwooddixon]

You've covered some basic points. Even with apparent injector knock I would expect it to turn over and start sooner.
I would suspect fuel delivery issues - maybe an air leak in the fuel supply or a lack of fuel supply.
Could the fuel be draining back from the engine whilst its stationary and it's taking that long to pump it back up to the engine?

 

[ajlsl600]

Did u check fuel pressure.?