Idle settings
 

ok can anyone give me any tips on how to keep my idle from bouncing up and down constantly, i tried changing some stuff but nothing seems to help, also getting on the throttle i get a big dip, should i adjust the acceleration wizard, specifically what and which way?

so there's no way to get a decent idle without a variable tps?

I've been struggling with the same thing. I found some guy on m.net that had success with an "85-87 735i" TPS. I found one similar on ebay (seems BMW had many similar TPS that worked on a range of cars in that era), which should arrive soon, and I'll give that a try. It would be a rather cheap solution ($13 shipped), if it works.

Try slowing down the 'fast recovery speed' to 10 or 15 hundredths of a second. I've updated our base settings a bit and found a combination that works a bit better and this was probably the biggest piece. The variable TPS makes a huge difference when coming off throttle coming to a stop with the AC on, but otherwise you shouldn't have oscillations like this. It's probably trying to adjust a bit too fast and getting into some oscillation.

You will need to restart the car after making the changes...

i'll try that, thanks

Is this why whenever I tried tuning the idle I could never get it right?

Not sure... I stated it for a pretty specific reason-- as he was having an oscillation issue, and in my experience when you're working on correcting that, once it starts oscillating, you can change the setting, but you need to restart the car to get it to settle down. Even if the new setting is right on.

That's the only idle control type situation I noticed this with however. Other settings always appear to take effect immediately and allow me to tune on the fly.

Warm-up idle tuning isn't that hard once you have the base values for your valve right.

Closed loop tuning is another story all-together, and it takes some time. It's officially 'experimental' code, and the documentation is a bit weak IMO. I had to work with it until it made sense to me, basically experimenting until I answered most of the questions I had about it. I'm fairly good at tuning it now and I've been contributing to the documentation some for MS1 Extra-- you should see some updates happening.

Thanks for that Jerry, I'll be honest and say I faffed around with the C/L-Idle for months. Whilst n/a I had it pretty good, but once I put the charger on it all went to pot, to the point where I've had to give up and give the stock ECU control. I just couldn't get it to stop fluctuating.

I've a feeling that some other part of my tune isn't good enough which is contributing to the problems however, as with the stock ECU controlling idle it takes a good heatsoak before the idle reaches a reasonable level, and once really heatsoaked it drops further still - setting the idle when this heatsoaked means it rev's it's arse off when cold!

Could be the coolant/IAT related air density that needs fiddling, but atm I have it set at a compromise as I've not had the time to mess with it...

I've also recently moved from Highres to standard extra code due to a missfiring issue with the high-res, and now with the loss of resolution my idle fluctuates with the stock ECU in control!

Have you tried playing with ignition timing to sort out the idle? I've found that having a few more degrees of advance at higher kpa idle speeds can help stabilize idle.

For example, my car idles with 13* at 850 rpm @ 30kpa. At 40 kpa it gets 14*, and 15* at 50 kpa. If MAP should drop at idle, the increased advance helps things stabilize. Changes in spark advance are going to affect things way before an idle valve. This is the only way I could remove my idle oscillations with the stock ecu running idle.

I don't have AC, but my car idles and comes off idle just fine without a TPS. It just needs good fuel and accel tuning.

Not tried that no, any chance you could e-mail me your msq so I can have a look?

richard dot priest1 at googlemail dot com

Thanks!

It's on the way.

gorrit! thanks :)