Need help with Idle & E-throttle

[Poussin]

Hello,

I'm Sebastien from France. I'm a newbee on the forum, but I'm a old Link user, I played with all versions of the link on my cars (G4 G4+ G4x vipec V88 ...).

I've build a rally car for one of my best friend BMW e36 with M42 engine and lot off bespoke parts:

Engine and ecu are new.

-stroked to 2.0L

-Full ported head 

-3D printed inlet manifold

-Seq gearbox

-68 mm DBW bosch motorsport throttle body

-...

It is the first time I use a DBW throttle, I need help for 2 on two points:

1-I have TPS & APS error accumulator, I try many differents setups but nothing change and I don't know why

have a look on error accumulator file ( log maded with engine stopped)

2-Impossible to have a correct Idle: I don't understand why the TPS never go to  0% when I'm off throttle a hight RPM.

TPS is locked to 4-5% and sometimes, the RPM never goes down.

If I decrase base idle position, the engine stall.

I tryed with open loop E-throttle + Ignition idle:  It reach Idle target,  ign° make jump from min to max clamp value, but engine sound like a running on 3 cylinders...

If you look at ign map,  I need to remove Ign° in RPM cells, without this, RPM never enter in Idle mode

If I leave a std Ignition map & off all idle function: TPS goes to 0%.

I Put 0.5% min in E-throttle target, below 0.4%,  Motor DC % increase a lot, and with 0% it goes on limp mode.

 

Can you explain me what is the dashpot setting ?

I Attached Map & Logs in the post.

Thank you for your help.

 

E36F2000-demarrage RAZ_7.pclx error accumulator.llgx idle.llgx

[Adamw]

Your APS and TPS error is because you have the (sub)100% setting set to 91%, it looks like both of your sub sensor work all the way to 100% so these should be set to 100%. 

 

 Your idle log is not very useful as the engine never enters idle mode.  The stall at log time 0:08, I assume this is you driving in overrun conditions with the clutch out?  The ecu closes the TPS from 3.9% all the way down to 2.1% without the RPM changing - something must be keeping the RPM above target. 

Can you change all the orange settings below and do a new log which actually has some idling in it. 

 

[Poussin]

Hello, thank you for your answer.

Idle is much better now, you can find the log attached.

The car is on neutral in my factory, engine is new and I wait to solve the probem before going on dyno to make the break-in and mapping.

The error accumulator is now solved: I put 91% in APS(100%) cell because with on WOT the throttle body open more than 90°

So now I put E-throttle 1 Target max value to 91% (have to valid this on dyno)

I still have 5% TPS in overrun:

 

idle-2.llgx

[Poussin]

another log.

I try to set the starup offset to 0 but TPS still around 5%.

you can see in this log that when I put a little throttle, the RPM goes up and never return to idle, I had to put throttle again and afer the rpm sometimes goes down to idle, but not every time.

If I desable all idle functions, TPS go to 0% and engine stall quickly.

 

idle-3.llgx

[Adamw]

1 hour ago, Poussin said:

I still have 5% TPS in overrun:

When you are outside of idle conditions the throttle will go to idle base position + offsets.  

 

57 minutes ago, Poussin said:

you can see in this log that when I put a little throttle, the RPM goes up and never return to idle, I had to put throttle again and afer the rpm sometimes goes down to idle, but not every time.

At log time 0:16 your engine required 4.5% TPS to idle at the correct RPM, but your base position table has 5% for that temperature and 0.4% dashpot offset.  So when you rev it the throttle will go to 5.4%, this is too much air so the RPM will never come back down below the RPM lockout to activate idle control.  Your base position table needs to have 4.5% in it for this temperature.  You can see also the E-throttle target is 5.4% but the TPS is at 6.2% for a little while, this means you need to increase integral gain in the e-throttle settings.  Try 0.05.

 

 

[Poussin]

Ok, I know understand the problem know

I'll try this tomorrow.

 

Many thanks Adamw

[Poussin]

Hello,

test ok !

Finnaly, 

-I've adjust base position idle for each temp

-increase E throttle integral factor to 0.5

-adjust dashpot 

Now we can go to dyno for break-in and tuning session.

 

Many thanks for your help