Binder

I've been fighting a terrible pulsing idle issue for some time now. Yesterday I got my WB O2 up and running and it shows idle being very rich, 9 or 10 to 1, this is in closed loop. In closed loop idle is fairly consistant RPM wise but if I let it go open loop it surges wild. Thing is the surge happens all the way up through 2000RPM or so well into closed loop. If I take fuel out of the main VE table to lean out idle it brings a rough idle and the surge comes back even at closed loop and the WB surges with the idle between 13 and 15 to 1.
I hope I explained this all in a way someone can understand.
This brings me to my question, I read this in another thread.

RBob wrote-"Using the Prominator Pro you can make real-time changes. This makes idle tuning a piece of cake. Observe the RPM & MAP with the WUD, and note where the engine surges in RPM. That will be a lean area.

Increase the VE% in the cells of that area. Observe result, if better, then continue on. If worse, back out some of the changes. Once the idle settles down, change the desired idle RPM. And tune that area. Go up and down the RPM scale some until it is all good. You may also find some areas that are too rich. If so reduce the VE% is those areas.

Then return the idle speed setting to where the engine should idle. And take it for a drive. Note how the engine returns to idle when coming to a stop. If it doesn't return to idle smoothly take a data log of it. Look at that area and make further changes.
RBob."

I don't have EBL like the person that this is refering to. Would this method of tuning also apply to me? Any other advice would be welcome too.

RednGold86Z

iTrader: (1)

Yes that applies to all MAP systems, but seems like you've got an O2 sensor problem (10:1 in closed loop means you're not getting good closed loop). Is it still installed? It should be, or have the 0-1V output of a wideband connected to the O2 input wire of the ECU.

Maybe you're thinking backwards between what closed and open loop is??

One thing that can help get your VE close, and to settle down the oscillations for tuning, is to disable all the loops. That means Spark, IAC, and Fuel closed loops. Make a separate bin with those disabled (may take a lot of work to get that done - but you'll learn a lot just carefully looking at all the tables involved).

My guess though, is that your light load VE's are too rich, then loop pulls out fuel, and leans it enough to reduce vacuum (which means IAC had to open some), then it's in a VE that isn't so rich, which combined with INT at 108 will be so lean that RPMs start to fall faster, and IAC opens more, INT races UP, brings power back up, RPMs race up, IAC starts to close, load goes down, VE is rich, INT goes down, peat and repeat.

Binder

You'r right, I did write this backwards. Open is fairly consistant and very rich while closed surges bad. When I tried to tune the idle today I set all of the cells to the same value in the idle range plus the cells around it. That leaned it out but that's when it runs rougher and AFR fluctuates around stoich.
How do I "disable all the loops"? I thought open was open, I didn't know there were different degrees. Yes the NB O2 is installed, the WB is running solo.
I attached the log file I took today while messing with it. I'm not sure how much good it is as I made lots of changes back and forth with the Ostrich while taking this log trying to get a feel for what the changes did. Tried to attach the O2 log file but it's in the wrong format. I'll have to figure that out later.