MSefi.com read only forum (Jan.15,2018)

I am tuning my 1987 BMW 535i, and at 180 degrees the enrichment is 0 which is fine. However at 180 degrees the car is idling at 850-900rpm at 13.7afm. The problem I have is that when the car reaches its maximum temperature of around 188, the idle then goes down to 12.3 and stuff. The cars best idle is around 13.2 However if I give it enrichment at 180, it starts to affect the overall tune more than I would want it to. What can I do about this? Or should I just tune it for that 188, and add enrichment even if the car is at 160-180 degrees? I have logs and msq if needed.

If I am understanding this correctly, you have a slightly lean issue when the WUE goes off and the temp increases to 188 right?
Doe the idle stay in the same rpm/kPa bin in the VE table? If not then just tweak the VE bin that the idle at 188 deg is in and drive on. Otherwise, you can change the high temp value for the WUE to 180 and just make it a very small value, (whatever is needed to put you where you want to be), and tune the idle for 188 degrees.

Good point on adjusting the VE table, sadly the values stay within the same grouping. My idle VE values are all the same number, so I had some constants when tuning. I'm going to play with it some more today, and see what I come up with, I was trying to avoid running WUE all the time. However after look at Peter Florances tune (we have the same basic engine, with same injector size) he had to do the same thing. The thing is it still wants around 106 WUE at 180 degrees, while at 188(ish) it's fine with none. So I think ve anaylze is going to be confused since there will be a changing difference in WUE as I drive once warm. I have a bin at 180 and 190 as of now, and am using like 106WUE at 180, than 100WUE at 190. It seems to work pretty good, but not sure how much it will affect the overall VE.

Scottinva wrote:sadly the values stay within the same grouping. My idle VE values are all the same number, so I had some constants when tuning.

Can you change the RPM values in the VE table to "home in" on the one you idle at, and isloate it?

Ya that is very true, maybe I can play with the resolution down there. What a great idea, thanks buddy.