I just figured out how to use datalog, so bear with me if I messed something up.

I feel like I've tried everything, but I just can't get the idle to hold steady. Right now, the BAC is set to PWM warmup. I just gave up on trying closed loop idle. I changed the idle area of the map again and again, but it goes super lean, then tries to die out, then goes super rich (expected, as I have that area of the map sort of rich to "catch" the idle before dying out) and bogs down really bad, then goes back to its normal area of the idle map and the AFR reads about 12.00 for about 3 to 5 seconds, rinse, repeat.

I'll go out and snag an .msq here in a few minutes. I'll also try getting another datalog of the problem, I just want to see if anyone sees any preliminary issues now that I've finally figured out how to do a datalog (which excites the **** out of me, I won't lie).

I guess I have to zip the .msl file in order to post it?

 

as promised....

Maybe someone can help out with my cruising surge as well.

 

Should include that it's an S4 TII. S5/To4B hybrid turbo, v-mount intercooler, 720cc secondaries, stock ports, running MS2 V3, MS2Extra 2.1.0d

 

I'll take a look, but you shouldn't really even try to tune closed loop if you don't have a stable idle with warmup only.

Ken

 

When BIT7 is set you have a large enrichment happening!

You go from 1.9mS PW to ~6.0mS somethings.

What is BIT7?

 

Also your PW looks very low.

Turn off the wb02 and put it away. I don't care what other people on this forum say. There is a process called 'Best lean Idle' tuning. I suggest you read up on it and then try and put it to practice.

Basically you want close to factory ignition timing, close to and above the factory idle rpm, and you want the minimum pulsewidth to do that, and then you can bog it down a few % in the fuel map to drop the RPM (bog it will fuel a tiny bit) and give it enough fuel padding to not stall.

 

I have no idea what all that ^ is about

I'll look into that though, I've learned to never turn a deaf ear to any help whatsoever.

I did find last night that I had some injector characteristics settings wrong. I have low impedance 550cc primaries, and low imp. 720cc secondaries. I had the injector opening time set to 1.0ms, and MSIIextra manual recommended 0.6ms. Also, I had the PWM time threshold set at 25.5ms, and it should have been 1.0ms for low impedance injectors. As well as the PWM current limit at 100%, when it should have been 30%. After changing that, it didn't want to run at all. I loaded the original base VE map that Aaron Cake posted on his website and wouldn't you know it, she cranked up and idled right away. Boosting was waaaaay rich, so I pulled about half of that out (Aaron said it was about 20% too rich, but my secondaries are much bigger than stock). After taking it out, it has about a 10.5 afr in boost, so I've got a little fine tuning to do, but it's MUCH MUCH MUCH better than it was. Idle's still just a little iffy, but I think that changing the idle area of the VE map can fix that.

I think I'm getting somewhere now! What do you mean by turning of the WB02? What window is that under? Also, what would that do by turning it off?

 

Idled pretty good after fixing all of what I stated above, but I still had a little bit of a choppy idle. Very slightly, but still there. Turns out that I had the "active above rpm" in the EGO control set too low. Only had it at 1000 rpm, but since I was still running PWM warmup, I had the BAC valve set to 40% open to obtain ~1400 rpm.

After fixing that, the idle was too rich, but very steady. I leaned it out some to around 12. I also set the BAC to around 30%, which obtains about 900 rpm, with AFR still right at 12. I think I'm going to try and verify the timing's right, now that I have a smoooooooooooth steady idle.

Then I can start getting into tuning closed loop idle.

 

You can't start tuning closed loop idle until the entire map, as well as the temperature corrections, are tuned.

 

Bit 7 is MAP accel enrichment by the way.

Your MAPdot threshold is too low for MAP accel.

Ken

 

The VE map has been re-worked, and I don't think that I need to fiddle with the ignition map since it's as close to stock as it can be, and I'm pretty sure that's right where I want it. My goal for this car is just street-driven performance, occasional track. I don't even have any power goals. Whatever it gives me, I'll be happy.

I've also gotten the warmup enrichments where they should be now. I won't know if anything under 75F will be right until things start to cool off, but every morning it starts right up and idles without issue.

Are there any other temperature corrections I need to worry about tuning before getting into closed loop idle?

I fixed that. It was way too low, but I bumped it up to 75 and it works quite well now. That still may be too low, but the .msq I posted was before I fixed the injector opening time setting. The only way I could get it to not die on me was to have the MAPdot threshold so low that it "caught" itself with a ton of extra fuel.

I also leaned out the acceleration enrichments alot. I can't believe how well the car runs. If only I could get the idle steady at a lower rpm, I'd be set. I had it yesterday idling at 900 rpm no problem. The engine was FULLY warmed up (engine bay fully heat soaked) and it idled great. When the engine has just warmed up to operating temp and it the warmup enrichment goes to 100%, it starts to want to die and idle funny. But once everything else is fully hot and it's been warm for a while, it idles fairly steady.

 

That tells me that one of the other corrections (MAT possibly) is not correct, and you've tuned it for when the engine is hot.

 

I'll get right on that good sir

Real quick though, I'm looking through the MS2Extra tuning manual, and I don't see any information about Required Fuel for rotary applications. Any insight about what inputs to get the proper amount? Namely stuff like displacement (1.3 or 2.6?) and # of cylinders (2, 4?) # of injectors? (2, I assume, right?). And I have 2x 550cc and 2x 720cc injectors, primary/secondary. Does that matter when crunching numbers for Required Fuel?

 

For required fuel, just set up as a 2.6L 4 cylinder 4 stroke.

I think setting up as a 2 cylinder 1.3L 2 stroke would give you the same result, but on ms2, I'm not sure that'll run your engine (On ms3, we have "rotary" for the stroke settings now).

Just use the primary injector size for req_fuel. Secondaries are entered into the staged injection settings.

Ken

 

I punched those numbers in to the required fuel calculator and tried driving the car with the new value only. Well, the old value was 10.0, new value was 8.0. Way too lean to drive. So I put it back to 10.0, then went into the VE map and found the tool where you can adjust the required fuel (in the basic settings) and it changes the VE map at the same time to compensate. I'm still not sure what that did for me, but after adding fuel to the idle area some more, the idle just stopped rock solid at 1000.

I know that the MS2Extra tuning manual says that the required fuel should be the injector pulse width, in milliseconds, required to supply the fuel for a single injection event at stoichiometric combustion and 100% volumetric efficiency. I don't understand how changing it and then the whole map would make everything work better, but it does.

 

It really shouldn't, but lowering the req fuel can give slightly better resolution in the VE table, so that might be what you're seeing.

Ken

 

Good point, I was thinking that too, but didn't have a word for it

So now that I have a solid idle, is it safe to say that I can start messing with closed loop idle control? I've been told by Aaron numerous times that I shouldn't start tuning closed loop idle the whole map including temp corrections are correct. I've gotten the warmup enrichment right finally (we'll have to see about the rest when it gets colder) and I started tuning the IAT correction. There's a graph that allows you to adjust timing based on IAT and one that allows a fuel correction % that I've tinkered with, but is there anything else that I should worry about before getting into it? I'd like to have closed loop working so that I can have air conditioning again without the car dying every time it goes to idle.

 

I'd say it's probably safe to work on closed loop idle.

Ken