(T) First take off jerky on cold starts, no fault codes

I can't see your timing advance data , have I missed something?

Try injector cleaner again too You may as well unless it's too expensive

It's almost as if the car knew to behave itself while running diagnostics!

Fuel trims appear to mirror themselves, so it's not telling much and are probably incorrect.

I have no clue if timing advance curve is typical for the rpms but it's quite sluggish at first and second gear which may be symptom of bad timing.

Accelerator and throttle position seem to correlate beautifully and also with map sensor, it appears to have direct correlation to throttle position. So no problem there!

Yes higher octane fuel might help !

I don't trust the scale on the side of the timing advance .
Neither do I trust that is long term fuel trim being graphed .

So you bay need a data tool you can trust.

But your car is running ok and not using excess fuel.

Doing well

Yes, probably all is well but it all starts with slightly ominous symptoms and then one day it's completely broken.


When the weather's warmer, i'll start with changing the leaky valve cover gasket. It's possible that some oil had leaked to the spark plugs.

So once again - starts are OK but driving on 1st gear causes fluctuations in rpms? And it's all gone when you shift 2nd gear? And only when engine is cold (mornings)?

It just did the same thing yesterday. It happens for the first 100 metres or less on first and second gear, then goes away. It's like as if it was misfiring bouncing a bit, running rich.

Hopefully it's nothing too serious.

As I remeber from Renault forum, when engine is cold, ECU is maintaining rpms mainly by coolant temp sensor. But these values can be visible via on-line diag. Of course there is a lot of other parameters to calculaye final rpm management...I tink the best way is online giag and person who understand all readings (not a guy like "there are no errors so its ok")

Now that weather's warmer it also does jerk on 1st and 2nd gear also with warm engine but it doesn't happen all the time. It may be two issues and sometimes it's the driver releasing the clutch too fast. I don't believe it to be worn clutch either.

Sure MES can tell injector and other calibration values and can probably tell which sensor values are off. Sometimes it's cheaper to change a sensor for 25€ than going to a specialist. Ckp- sensor is one sensor to replace on my list. I had to peek under the timing belt cover, and had to touch the ckp- wiring once. That made the car behave itself for several months. It may be worth checking. What do you believe to be the correct resistance value for that sensor?

Ckp..?

Crank position..??

I think that sensor is an Hall effect one, so you won't read any significant value since it delivers something like a square wave reflecting the teeth pattern on the pulley ...

BRs, Bernie