[bartbes]

Hee guys, just installed pure stage 2 turbo's, new 02 sensors, boost solenoids, vacuum hoses etc. Did a adaptions reset with inpa and I still can't get rid of these fluctuations.

This is a from log cruising on the highway.



Any insight of what might be causing this is much appreciated!

Thanks, bart

Edit: I lowered dwp from 35 to 25 and it got a little better. This is already with mhd rattle fix set to 25% so I can't go much lower but I wil try tomorrow.

Edit:So I set the mhd rattle fix to 10% today. The pigeon sound under the hood that sometimes occurs on part throttle seems to be gone, but the power on off/ surging feeling when cruising is still there. Afr also looks different after lowering rattle fix settings

Solved:fluctuations solved by having all adaptions reset by the dealer, surging solved by switching back to stock diverter valves, weaker springs on the forge ones may work as well

[bartbes]

Throttle seems steady in the last log, but the car still feels the same while driving. Running forge dv's and pure stage 2 turbo's. Checked everything for leaks. Any idea's of what I can check next? Thanks

[Chris@VargasTurboTech]

I had a similar issue when I made the switch to MHD. I posted about it somewhere along here... bottom line had to reset adaptations via Bavarian Technic. There is something that needs to get reset that MHD doesn't do. I haven't played around in INPA much, not sure if the adaptations are the same. C.Warren and Wedge know about this as well.

Post 6:
http://www.e90post.com/forums/showth...n#post20840806

[3000GT MR]

That oscillation in the second picture is normal. Its more pronounced the higher in ethanol content you go. This is called "phasing" and its a way the lambda signals get reported and filtered. It will only happen at low to medium load when the DME is controlling cylinder individual lambda control (CILC) After 4500 rpm it will read more flat.

How much Ethanol are you running?

[bartbes]

Originally Posted by Chris@VargasTurboTech

I had a similar issue when I made the switch to MHD. I posted about it somewhere along here... bottom line had to reset adaptations via Bavarian Technic. There is something that needs to get reset that MHD doesn't do. I haven't played around in INPA much, not sure if the adaptations are the same. C.Warren and Wedge know about this as well.

Post 6:
http://www.e90post.com/forums/showth...n#post20840806

Thanks Chris, I don't have BAVtech available and I did the inpa reset because wedge advised me to since he is also setting me up with my tune. I believe wedge is currently on a holiday. Maybe I missed something or did something wrong while resetting, it did'nt seem that way but I will try again. I am also trying to rule out any hardware issues.

Edit: I am going do the dealership next week for a software update on my steering collom module. Maybe they can do the the adaptions reset for me?

[bartbes]

Originally Posted by 3000GT MR

That oscillation in the second picture is normal. Its more pronounced the higher in ethanol content you go. This is called "phasing" and its a way the lambda signals get reported and filtered. It will only happen at low to medium load when the DME is controlling cylinder individual lambda control (CILC) After 4500 rpm it will read more flat.

How much Ethanol are you running?

Thanks 3000gt mr, but is it also normal to feel these fluctuations in my seat while driving? It is realy anoying like getting a push and a pull the whole time. Cruise controll is the worst. I do not run any ethanol yet, this is on 100% 98RON fuel

Thanks for the input guys

[3000GT MR]

Originally Posted by bartbes

Thanks 3000gt mr, but is it also normal to feel these fluctuations in my seat while driving? It is realy anoying like getting a push and a pull the whole time. Cruise controll is the worst. I do not run any ethanol yet, this is on 100% 98RON fuel

Thanks for the input guys

The first log i could see having those pulsation while driving your throttle isnt constant. If you have new turbos why are you bothering with the wastegate rattle fix? I'd put the MHD back to stock val along with the JB4. Whats your WGDC during this fiasco?

[bartbes]

I do not have jb4, mhd custom flash only.
I am using rattle fix to try to get rid of this problem, in the first log it was set to 50%, in the second log it was set to 10%. That is the only thing I have changed and what made the difference between the logs. I also had to use the rattle fix to solve the surging under light load issue, I found a thread where another member with the same problem solved it that way. In the first log wgdc was between 35/40, in the second log it's the light bleu line.

I would like to drive the car not using rattle fix as lag increases and exhaust is very loud all the time. But it seems it does'nt run well that way

[3000GT MR]

Originally Posted by bartbes

I do not have jb4, mhd custom flash only.
I am using rattle fix to try to get rid of this problem, in the first log it was set to 50%, in the second log it was set to 10%. That is the only thing I have changed and what made the difference between the logs. I also had to use the rattle fix to solve the surging under light load issue, I found a thread where another member with the same problem solved it that way. In the first log wgdc was between 35/40, in the second log it's the light bleu line.

I would like to drive the car not using rattle fix as lag increases and exhaust is very loud all the time. But it seems it does'nt run well that way

oh yeah durr i should have noticed with the logs you posted. I saw DWP and automatically thought jb4. If anything id do a throttle adaptions reset and get a base tune from Wedge if that thats the road your going down to see if that clears it up. Throttle oscillation is a common complaint on some N54's and sometimes tuning is the solution. Mean while i would just do a once over on your vacuum lines from wastegates to vacuum pump and ensure all is good there.

[bartbes]

I already did a throttle adaption reset through mhd, and inpa. I am currently on the 3rd revision with wedge on a 98RON custom tune and waiting for him to pick it up when he gets back from his holiday. I replaced and double checked all vacuum lines and all seems well, i even have vacuum release pulling a hose long after the car has shut down.

[Jeff@TopGearSolutions]

What BOV are you running? If TIAL, did you tap your intake manifold for a larger 1/4inch fitting and 4MM line?

[bartbes]

I'm running forge dv's with yellow springs. 1/4" tapped nipple with a 4mm hose split into 2x4mm. Should I tap a second nipple and run them both directly from the intake manifold?

[cwarren]

Have the dealer do the reset/updates to control modules bet it goes away.
This oscillation problem is becoming more and more prevalent wish I knew what the root cause was . For some reason the adaptation reset with INPA or BT does not correct the issue .

[bartbes]

Originally Posted by cwarren

Have the dealer do the reset/updates to control modules bet it goes away.
This oscillation problem is becoming more and more prevalent wish I knew what the root cause was . For some reason the adaptation reset with INPA or BT does not correct the issue .

Taking it to the dealer tomorrow. I do believe it is related to throttle and lambda adaptions so I realy hope they can fix it for me. Maybe installing new 02 sensors is what started this problem.

[Jeff@TopGearSolutions]

Originally Posted by bartbes

I'm running forge dv's with yellow springs. 1/4" tapped nipple with a 4mm hose split into 2x4mm. Should I tap a second nipple and run them both directly from the intake manifold?

Nah that's like not it then.

Originally Posted by cwarren

Have the dealer do the reset/updates to control modules bet it goes away.
This oscillation problem is becoming more and more prevalent wish I knew what the root cause was . For some reason the adaptation reset with INPA or BT does not correct the issue .

I actually have a small oscillation I've been fighting for a while too now that you mention it. Resets help but are not 100% fixing it.

[ferocity02]

The lambda oscillations are normal.

Can you feel the throttle oscillations. My only thought is that the turbos are making more boost than the DME expects with all of the upgrades. So while cruise control is active it is constantly overshooting/undershooting. Reducing the DWP creates less boost while cruising so it's more predictable for the DME or closer to what the DME expects.

[bartbes]

I could realy feel it yes, especialy on a cold engine. Had a full reset at the dealer today and so far so good, no oscillation or surging while cruising, even with cruise controll on. Dwp still at 15% but I am going to try setting it higher with stock dv's on. Could be boost overshooting the DME target, but the problem only occurs when the engine is in vacuum, so that would be less vacuum then expected? If so, this could be tuned out right?

[Chris@VargasTurboTech]

Originally Posted by cwarren

Have the dealer do the reset/updates to control modules bet it goes away.
This oscillation problem is becoming more and more prevalent wish I knew what the root cause was . For some reason the adaptation reset with INPA or BT does not correct the issue .

You can do a CAS reset with BT.

[bartbes]

So I put on the stock dv's, disabeled mhd rattle fix, and the car runs perfect now. Wgdc while cruising is about 40/50 % and no surging. Boost holds fine but im only pushing 22 psi max

[Jeff@TopGearSolutions]

Originally Posted by Chris@VargasTurboTech

I had a similar issue when I made the switch to MHD. I posted about it somewhere along here... bottom line had to reset adaptations via Bavarian Technic. There is something that needs to get reset that MHD doesn't do. I haven't played around in INPA much, not sure if the adaptations are the same. C.Warren and Wedge know about this as well.

Post 6:
http://www.e90post.com/forums/showth...n#post20840806

Just saw this, going to try later. I'm actually one of the few still with a Bav Tech tool.

Originally Posted by bartbes

So I put on the stock dv's, disabeled mhd rattle fix, and the car runs perfect now. Wgdc while cruising is about 40/50 % and no surging. Boost holds fine but im only pushing 22 psi max

May have been that rattle fix but I never used that feature since I don't have any.

[RSL]

If you're still on stock pedal mapping, have any of you tried adjusting the torque request a little "deader" in those cruise load areas? Things have changed everywhere with added flow of larger turbos, that includes the low vacuum-to-low boost/low load/low pedal areas. It's probably less of/not an issue on ST.

[carcars 335i]

Originally Posted by bartbes

I'm running forge dv's with yellow springs. 1/4" tapped nipple with a 4mm hose split into 2x4mm. Should I tap a second nipple and run them both directly from the intake manifold?

Usted debe utilizar muelles azules o mejor rojo y solucionará su problema. Yo he luchado con este problema durante mucho tiempo.