CSL airbox +288/280 cams jerking on low speed

[BMWfanz]

Guys, need help with tune of idle map. Installed on my swapped E30 CSL airbox and 288/280 12.5 Shrick cams, currently my tuner is doing custom tune. Got problem with low speed jerks on 1st gear with closed throttle- car starts jerking until I slightly open throttle, already tried to rise to 1000rpm idle- advanced and retarded ignition- all is ok on 12.5-13.5 AFR, but when O2 sensors correct AFR to 14.7-15- car starts jerking. Maybe someone has same setup and can help with some info.

[Tomba]

Sounds the mixture is not near lambda 1 from mapping and the controller goes bananas. If there are large differences in the mapping the lambda controller has to correct to much. Try to run open loop and observe the lambda/AFR. Correct mapping to lambda 1 / 0.95 and observe.
In Tool32 there is a "job" to turn off the lambda regulation, lambda_regler_sperren or something. Run that job and see if you have the same issue.

Are you running CSL software too?

[S54B32]

I would say you have not correct fuel mixture inside chamber but think you have correct mixture because AFR gauge shows this. But due overlap maybe this reading is wrong. I would suggest to tune the lower load sections of Vanos tables, but this takes obviously more time than only a WOT tune…

of you really are sure your AFR is 100%, you can permanently disable lambda adaptions and regulation inside tune in different ways. (Config.Bitfield, ready state, thresholds etc)

Btw:
I hope you don’t use a tailpipe sniffer for AFR readings?

[BMWfanz]

Sounds the mixture is not near lambda 1 from mapping and the controller goes bananas. If there are large differences in the mapping the lambda controller has to correct to much. Try to run open loop and observe the lambda/AFR. Correct mapping to lambda 1 / 0.95 and observe.
In Tool32 there is a "job" to turn off the lambda regulation, lambda_regler_sperren or something. Run that job and see if you have the same issue.

Are you running CSL software too?

Yeah, I have 0401 CSL software. Ok will check this and post the results

[BMWfanz]

I would say you have not correct fuel mixture inside chamber but think you have correct mixture because AFR gauge shows this. But due overlap maybe this reading is wrong. I would suggest to tune the lower load sections of Vanos tables, but this takes obviously more time than only a WOT tune…

of you really are sure your AFR is 100%, you can permanently disable lambda adaptions and regulation inside tune in different ways. (Config.Bitfield, ready state, thresholds etc)

Btw:
I hope you don’t use a tailpipe sniffer for AFR readings?

I"m using AEM wideband mounted after my main stock 02s, located in x-pipe after euro headers. And I have Testo logger with connected via com port too for mixture logging.

[BMWfanz]

I would say you have not correct fuel mixture inside chamber but think you have correct mixture because AFR gauge shows this. But due overlap maybe this reading is wrong. I would suggest to tune the lower load sections of Vanos tables, but this takes obviously more time than only a WOT tune…

of you really are sure your AFR is 100%, you can permanently disable lambda adaptions and regulation inside tune in different ways. (Config.Bitfield, ready state, thresholds etc)

Btw:
I hope you don’t use a tailpipe sniffer for AFR readings?

Is config of 288/280 cams are compatible with stock O2s or all tuners are disabling them? Or my tuner need some corrections in tune for lambda maps or parameters?

[SliM3]

Log your cam position at idle and make sure the exhaust cam isn't retarding, subsequently creating excessive overlap. Intake should be at 60 (130 ATDC) and exhaust at 0 (128 BTDC).


Sent from my iPhone using Tapatalk

[BMWfanz]

Log your cam position at idle and make sure the exhaust cam isn't retarding, subsequently creating excessive overlap. Intake should be at 60 (130 ATDC) and exhaust at 0 (128 BTDC).


Sent from my iPhone using Tapatalk

Partially solved problem by changing intake Vanos on idle rpms from 60 to 50, and zeroed exhaust vanos angle too, now much better.

[BMWfanz]

I would say you have not correct fuel mixture inside chamber but think you have correct mixture because AFR gauge shows this. But due overlap maybe this reading is wrong. I would suggest to tune the lower load sections of Vanos tables, but this takes obviously more time than only a WOT tune…

of you really are sure your AFR is 100%, you can permanently disable lambda adaptions and regulation inside tune in different ways. (Config.Bitfield, ready state, thresholds etc)

Btw:
I hope you don’t use a tailpipe sniffer for AFR readings?

Reduced intake Vanos angle and zeroed exhaust vanos angle at idle solved problem. I will create new thread with my step by step tune, I think it would be useful, I understand that better is to go by easy way and buy tune from HTE but it is interesting to do it by myself for me))