zek

I found this comment on another engine management fourm (unrelated to Link) 7-08-2013 - I just tried camshaft control on M54B30 - double variable VANOS with two solenoid valves... ...and faced with following camshaft control problem: PWMing has wide 'dead zone' where camshaft stays in fixed position. Somewhat like from 35...60%. So current strategy works very robust reqires P=255 and high I value. But once pwm crosses dead-zone margin, camshaft movement is 1)already delayed 2)too sharp. Here is another log with duty cycle. I do not have any oscillation issues at idle but I have RPM lockout set at 1800. http://i.cubeupload.com/ATHSl5.jpg

Apologies for using that questionable image hosting site!

Here are the images: http://postimg.org/image/58ydoj2ix/ http://postimg.org/image/btruq43gz/

Use the M52 preset for both the trigger and Vanos settings. I have Dual Vanos setup on my M54 and this is what I had to do.

Thanks for the offer JCE, I think I am OK now as I went out last night and tried using MUCH larger accel sense / clamp values and this appeared to work very well. Ben

I am attempting to tune accel enrichment on my twin screw supercharged BMW 330 and I am not having much luck. I am seeing a lean conditions of up to 22 AFR when apply the throttle at aything more than moderate amounts - it also happens when changing gear etc. The accel enrichment seems to stop the inital lean spike but drops of and this is where the spike occurs, I have tried various settings but it seems impossible to get something that works without making it really rich when driving normally. I think the problem stems from the fact I see 15 psi of instant boost the moment I open the throttle and it stays pretty constant throughtout the RPM range, only dropping of a little at high RPM. I imagine this is different to turbo / centrifugal setups which are more common. Does anyone have any pointers on how to tune for this type of scenario? there is not anything in the supplied base maps that seems to work. I am using TPS/MAP mode and have tried similar settings to many of the supplied basemaps. I know injection angle can affect this, so I am using 420 btdc at anything out of idle. Regards, Ben

Thanks Scott, Good to know, I will give that a shot! Cheers, Ben

Would it be possible to add a feature that allows any aux out to work with the idle up feature? I have dual heat exhanger fans and also my engine fan is controlled off a PWM output so no option to use the idle up feature. When either fan kicks in I have a problem with stalling at low speed. Tuning the idle control valve settings helps a little but it can not overcome the heavy load that my engine occasionally sees at idle (twin crew supercharged + lightweight flywheel). Would it be possible to wire up a digital input from the fans so I can use it to trigger the AC idle up feature instead? Thanks

My V88 also keeps turning knock control off randomly also, but I run the external interface. Unfortunately not got round to sorting it yet, but just throught I would chime in.

Well the Bosch DBW throttle is installed and my initial thoughts are that I like it much better than the Siemens unit. It has a weaker return spring, so feels more responsive and seems to track more accurately. One thing I had to do was put the deadband to 0.4, otherwise the throttle would try and close too much causing the Min DC limit error. (the exact opposite of my last problem ) Ben

I swapped the Siemens throttle body for a Bosch 84mm and things are looking better - Will know after the weekend once I have made another adaptor plate. I don't think it was possible to tune this problem out as the throttle would not close at the same position all the time.

Thanks Dave - I will try more subtle PID adjustments, I think this will be the key to cracking it. My throttle settings are: P = 8 I = 0.145 D = 30 Max Clamp 90% Min Clamp -90% Frequency 10000 Hz Deadband 0.1% Good to know there are other options, I will do some more experimenting. I have got it calibrated to the point where it only occasionally hangs a few hundred RPM over target now so not terrible. Ben

I have a bosch 3 wire ICV. Being an 80mm throttle and having an ICV It only has to stick open a fraction of a percent to cause idle problems. Ben

Thanks guys, Over the past week I have had fun messing around with this. Unfortunately the calibration is still proving to be a pain as if I do a manual calibration and press the throttle closed at points during calibration it will then cause the E throttle to go into safe mode later on. The only method that works is to perform several auto calibrations and choose the one that is most accurate after road testing. I also tried various PID combinations, but there is a small margin that If I go outside it will not calibrate. I am going to try another throttle body to see if I can get any improvement. If not I don't think I am going to fix this unless there is some kind of semi auto calibration mode available. Ben

Thanks Dave, I pushed the throttle closed before I started the calibration and this has helped, but as the E throttle calibration process is automatic I could not find a way to set the closed value individually.

I recently swapped my 68mm BMW electronic throttle body for an 80mm version. It works, but I have an issue with the revs hanging when at 0% TP. It happens when the ECU applies a duty cycle of less than 50% with the throttle closed (0% TP) - this causes the butterfuly plate to not seat fully against the bore causing a vacuum leak. U I assume the difference in position is too small for the throttle position sensor to pick up, so it thinks it is at 0 but is not. I have spent some time experimenting with the PID settings, which has helped a little but not solved the problem and I am afraid to mess things up. Is is possible to request a feature that prevents the duty cycle from going under a set level at 0% TP? Not sure what else to try. Ben

Made a little progress - I have got the interface to work with the Vipec but only intermittently. It appears the ECU is disabling the knock control on about 50 percent of startups because of a DI5 pulllup error. The knock input is configured to DI6, and pulllup is turned off so I don't know what is causing it to be disabled intermittently.

Sorry guys, if you are having troulble with that link I have zipped a wav here. (can not attach wav files directly ) knock01.zip

Edit: see below

Hi - Just going through the process of setting up my Vipec digital knock interface with my V88 and would appreciate some help. The first query is regarding the knock frequency - I have recorded and analysed several instances of knock all appearing clearly at 11.3 Khz. This is odd however as my cylinder bore is 84.5mm - putting the calculated frequency at around ~6.8 khz, or ~13 khz 2nd harmonic. Is this due to my knock sensor type? - (I am using stock siemens sensors, the engine is a BMW M54B30). I am unsure if I need to set the knock filter at 11 khz narrowband or use the 2nd harmonic wideband setting? I have attached 2 instances of knock (recorded in wavepad). The next problem I am having is the ECU does not appear to be receiving a digital knock feedback signal from the knock interface, I have checked wiring and software settings, but the ECU is not seeing any frequency reading from the input, so the knock system does not work. - I will hook a scope up to the knock interface over the weekend to test the output - but just wondering if there is anything else I should check or is there a way to test the interface? Thanks, Ben