Sounds like you have had some good work done here. I am curious if it runs ok when it is off idle? If it runs porloy off idle, then I would say the timing belt is one tooth off and need sto be corrected. If it runs smooth and has its normal pick up, then I would move on to the next couple of things. 1) I would make sure the inside (throat) of the throttle body is clean and not gummed up. This can hinder the idle just enough to cause the issue you are having. Use brake wash and a rag with the engine off to clean it. 2) Next, Making certain you have good gas in it(assuming it hasn't been setting for a long time). I would double check the timing if equipped.3) Check for any stored

Hello Dave


I uploaded a vemslog of last night from cranking to stall, shows the need to press the throttle and the gas press-stall thing

http://vems.hu/vemstune/sharingcenter/reports.php?cmd=view&key=OGT4zZ

Thank you

Joseph

Hello Joseph,

If you make another vemslog for me to review, i can take a look to see if i spot any offending behavior on drop to idle. I would certainly start out with some base fuel mapping before enabling any cam control or other to get a general feel for the system setup.

To get the idle setup tuned, i would advice to start with PID (all values) = 0 and tune the reference PWM table so the engine rpm rides around 200 rpm higher than desired target RPM (for that temperature). Also it is imperative that a higher value in table produces a higher rpm, if this is not the case the idle control channel needs to be inverted.

To get you going, my settings are as follows: iac pwm frequency 100hz, max pwm duty 100%, min pwm duty 0%, cranking position -40 60%, cranking 77 20%, reference curve -40 60%, at 80 (deg c) 30%.

If you have setup up the reference table to your satisfaction, this should also solve the stalling on return from 1500 -> idle, you are then ready to re-enable PID control, but only when reference duty-cycle is setup.

My PID settings: asymmetric control of, P 30, I 25, D 100, integral decrease 45, increase 15, deadband 20, integral minmap 22.

Best regards,


Dave

Hello Dave,

Well, after following your advise yesterday, the car ran MUCH smoother and I am actually much happier now ;)

However I still can't get the car to idle if I leave it to drop from 1500 RPM + it just drops dead and stalls. I have to lift my foot gradually and leave it by 1200-1100 so it can idles. It is still much better than before though where it used to stall in any case.
Although of note, when I am cranking, I noticed I should blip the throttle a little to let it start, then it idles right away. Idle PID now is 80-2-15, limits are 80-40

I will actually need some help later concerning the cam timing and the knock control from your experience:)

Thank you :)

Joseph

Hello Joseph,


Thanks for the positive referral, we always love having feedback like that.

The req fuel should be reduced because with your current VE table the measured lambda is much richer than desired (from lambda target table) using lambda 1 as desired for idle your req fuel would need to be scaled, new req_fuel = 13 (current) * 0.79 (measured lambda) = 10.27. for reference i also have 10 in my car (daily driver). Take care this is of course also VE table value dependent but, with 10 you should have enough range and should get you around 100 VE at 100 kpa.

When increasing the injector size (from 240 to 650) you would need to rescale req fuel yes, but as VE table will already be tuned than it should be a simple rescale of: bigger injector req_fuel = 10 (current 240 inj size) * (240/650) = 3.7.

The login/password is not linked to your forum account, they run on separate systems.

My car is BMW e30 with m54b25 engine (stock, without turbo), removed the DBW throttle but apart from that running full OEM hardware, including active thermostat, DISA, dual camshaft angle control (inlet/exhaust), dual knock sensing, dual lambda control, stock idle valve etc. Runs perfect (apart from some minor leftover tuning still todo).

If you have any further questions, feel free to ask.

Best regards,



Dave

Hello Dave

I will try that and get back to you
I am just a little confused, following the formula for 240 cc injectors gives actually 13.5, why would I reduce it? Is that a matter of trial and error??

I would later change them to 650 cc injectors, so the calculation gives 5, would I also need to change it???

I will try that later today anyway and get back to you

By the way is there a login and/or pass for this site and the forums?

Thank you Dave, you have been a real supporter and I am actually telling my friends here about that fast and amazing support ;)

Can you plz tell me more about your car? You mentioned already it is a M54B25...

Hello Joseph,


I would start by reducing the req fuel to around 10 and disabling low map fuelcut (currently set at 28, reduce to around 18) this should at least solve the rich running condition. And stall on overrun (low map).

Until the VE map is properly tuned i would disable all acceleration enrichment (all percentages to 0) and disable IAC follows tps when not idle (in idle settings general).

The rest just seems to be tuning.

Best regards,


Dave