total timing drop during cranking

[taronsargsyan]

Hi

I have strange issue. When car is hot and it was parked for 20-30 minutes and I try to start the engine it hesitates rpms goes up and down andy it might not be starting at all. If i shut it down and start again it starts fine. I have already checked all kid of mechanical issues which could be caused by the injectors, air leak and whatever but still no idea what is going on. I have rechecked the logs and what I discovered is when starting after 30ms it drops my final timing from 7(setup on start tables) to -6.

can someone take a looks and give me the hint ?


https://drive.google.com/file/d/1UZyhzT ... sp=sharing

this is N54, DI, S7plus. Audi coils.

regards

[taronsargsyan]

looks like torque limit trip is getting triggered.

torque limit trip.jpg (224.22 KiB) Viewed 17979 times

379659686_1457416661781429_7990046312068827946_n.png (365.88 KiB) Viewed 17979 times

anyone knows where is this configured ?

regards

[stevieturbo]

no idea on the torque limit.

But you do not appear to have the lambda working correctly, it's only logging whole numbers. Odd.

There are a couple of huge "knock", noise spikes on cyl 1 then cyl 6. Like really huge whatever is causing the noise not long after starting.

Something very weird is going on during cranking, and around the time of the timing change, where runmode goes from crank, to stop, to crank, yet shows an rpm reading throughout.

Timing might be getting pulled back via idle control, but you are not logging enough to see if that is the case.

Has it ever been setup and tuned correctly ? has it ran correctly ? or new install ?

Even right at the start of the log, runmode says stop, yet it is clearly cranking as it has an rpm reading. Which seems odd.

And for some reason your DBW target shot up to 100%, yet no movement at the pedal. This appears to be during cranking, around 380rpm....I can't see why anyone would ever want the throttle to be aiming for 100% during starting though.

[taronsargsyan]

this is new setup, though it is ongoing for more than a year(many issues has been fixed meanwhile).

The lambda issue is new on past logs it was perfectly fine, but with the same torque limit issue when not starting. I will recheck the lambda now.

2023-09-01 14-09-10 plus 0h00m00s S7#12516.SD

(515.9 KiB) Downloaded 545 times

and I can actually hear the knock honestly. This is forged engine I was just assuming this are the piston noise as they just stop after it starts, maybe I do heave loose injectors which leak? I will recheck

the runmode drops to crank after run because rpm drops lower than 600rpm which is runmode crank threshold, this is cause because engine cant keep up the running ?

looks like timing is being pulled back by 13.9 through trqIgnTrd which is most likely activated by LORQUE LIM TRIP.

and maybe noise is appearing because of the liming drop ?

regards

[stevieturbo]

trqignretard is just the value, not the reason. Find the reason.

if you can hear that knocking/noise, you need to establish what it is and prevent it from happening. It can't be good for the engine. And no, a timing drop would not cause it.

you need to be logging more relevant items, to find out the reasons for the trip etc.

Really you'd be better seeking out a competent tuner to look at it. More so if it's a new install that has never run properly to ensure you do not cause any harm if some settings are incorrect, or there is a mechanical issue.

[taronsargsyan]

the issue with timing correction is related to torque limit raised by TCU.

[stevieturbo]

You'd be better asking here, as you may get someone there who can offer remote assistance, if there is not a suitable dealer more local to you.

https://www.facebook.com/groups/529817494434981