RPM occasionally fluctuates with AC Compressor on

[0-60motorsports]

Another Update -

I chatted with Kassel tech support on the phone this morning. They say they've seen this before on some CSL intake conversions - and are going to do some monitoring and tweaks via remote desktop to my laptop connected to OBDII. That will probably happen on Wednesday, because I have to put the intake back on first. I'll post back with what we find.

Sounds good. Good luck. Might want to try HTE tuning off that doesn't work out.

[heinzboehmer]

Bry5on mullet tune is the way to go if you want the most drivability

[0-60motorsports]

Bry5on mullet tune is the way to go if you want the most drivability

That too.

[Andratch]

Sounds good. Good luck. Might want to try HTE tuning off that doesn't work out.

I had a colleague mention them as well. I'll check out mullet tune too. I definitely just want the most drivable, reliable tune...this isn't my fastest car, and I don't need to sacrifice reliability for a couple extra HP.

Interestingly, Kassel's take was that Alpha-N wouldn't help because the 'issue' is related to load, or something like that. I'm not sure I follow, but I'll make sure I get a good understanding of any changes they make if it works. I have a new ICV arriving tomorrow....I'm going to swap that in before I put the intake on so that I can just wipe that from the potential causes. My current one is original, and while it definitely moves freely and does seem to be functioning, perhaps it's faulty in some way.

[0-60motorsports]

I had a colleague mention them as well. I'll check out mullet tune too. I definitely just want the most drivable, reliable tune...this isn't my fastest car, and I don't need to sacrifice reliability for a couple extra HP.

Interestingly, Kassel's take was that Alpha-N wouldn't help because the 'issue' is related to load, or something like that. I'm not sure I follow, but I'll make sure I get a good understanding of any changes they make if it works. I have a new ICV arriving tomorrow....I'm going to swap that in before I put the intake on so that I can just wipe that from the potential causes. My current one is original, and while it definitely moves freely and does seem to be functioning, perhaps it's faulty in some way.

I also just discovered my ICV lower hose cracked at the connection where the clamp is. F that shit is expensive at almost $90!

[Andratch]

MINOR UPDATE -

Swapped in the new ICV today. I did not notice any difference - the Idle is still smooth without AC Compressor on, and fluctuates up and down when the AC Compressor is engaged.

https://youtu.be/i3i6QgGVS0I

I am going to put the air box back on and do a remote diagnostic session with Kassel tomorrow.

[cornerbalanced]

I have owned...6(?) E46 M3s, ranging from 28,000 miles to 180,000 miles. All of them have done this. Don't necessarily see what the issue is?

[Andratch]

I have owned...6(?) E46 M3s, ranging from 28,000 miles to 180,000 miles. All of them have done this. Don't necessarily see what the issue is?

The issue is a huge fluctuation in RPM while the AC is on, which dims the lights, sounds embarrassing, and makes it almost stall especially at take-off. And living in Texas, the AC is always on.

[0-60motorsports]

I have owned...6(?) E46 M3s, ranging from 28,000 miles to 180,000 miles. All of them have done this. Don't necessarily see what the issue is?

Which is not normal at all! So that means you didnt bother to find and fix the problem

[0-60motorsports]

The issue is a huge fluctuation in RPM while the AC is on, which dims the lights, sounds embarrassing, and makes it almost stall especially at take-off. And living in Texas, the AC is always on.

Have you checked your alternator? This might not be a tune issue......

[Bry5on]

Sounds to me like a tune issue, probably fueling around idle above .3 or .4 % relative opening. Your adaptations are probably fighting you here. Doing the Pavlo short term fuel trim tuning trick would certainly be helpful. As Heinz said, the mullet tune should get you back to stock airbox levels of driveability if you want to kill the problem dead.

[0-60motorsports]

Sounds to me like a tune issue, probably fueling around idle above .3 or .4 % relative opening. Your adaptations are probably fighting you here. Doing the Pavlo short term fuel trim tuning trick would certainly be helpful. As Heinz said, the mullet tune should get you back to stock airbox levels of driveability if you want to kill the problem dead.

Still wish you could do some remote tuning for us far far away LOL

[Bry5on]

Still wish you could do some remote tuning for us far far away LOL

I’ve sorted out how to do remote flashes, but not enough time available to do remote dyno tuning or anything like that. There are a few cars running around with either the US or euro mullets that were flashed remotely now.

[0-60motorsports]

I’ve sorted out how to do remote flashes, but not enough time available to do remote dyno tuning or anything like that. There are a few cars running around with either the US or euro mullets that were flashed remotely now.

Thats awesome! I am running the modified CSL file as I have everything CSL including flap, MAP, IAT sensor, Rail, etc MINUS Cams.

[Andratch]

Have you checked your alternator? This might not be a tune issue......

Yeah, 14V with the AC on or off. It would seemingly randomly drop to 13.5-13.9 for a couple seconds, but never below that and then would go back up to 14V.

And strangely, last night when I put the airbox back on and started it up, the idle was level with the AC compressor running until I kicked the SMG selector from N to 1, and then it started fluctuating for a few seconds and came back to level. Then this morning it was pretty stable for the first startup, and then it started fluctuating (only with AC on).

I'm getting on the phone with Kassel to do some tweaking here this afternoon,