Idle VE Table Values?
 

Hey there guys,

1.8L 1994 Miata, stock engine. Running MS2 V3.0 with current firmware (3.4.2)

Got my car running and im tuning my idle right now (Just idle). The base map I had gave VE values between 30-40 in the idle range, and ive found that in order to idle comfortably, I need to run like 13-17 VE values.... Is that normal? Those values put me right around 14 AFR. Im running about 10 degrees advance around the idle points for spark. Go easy on me, Im an MS newbie.

https://cimg9.ibsrv.net/gimg/www.mia...6801e96b41.jpg

NOPE

perhaps check that your req fuel is calculated correctly?

hmm, that looks good to me. I wish I had more for you but that's all I've got.

Some setting/calibration is definitely off. FWIW my idle VE cells are ~55 (1.6). I'm sure it's some random setting that needs to be flipped/adjusted. I'm just not experienced enough to know which.

Edit: Is your WBO2 and TS AFR reading the same?

Dead time is too long. Low battery voltage at idle can also be problematic this way. That VE step in the RPM domain is way off. If that is really what autotune is doing, they you have a system level issue.

Edit: I see you are just tuning idle. The MS2 voltage correction for dead time is ... poor. You can zero it out initially to get dead time more in order.

post a tune

And a log

You can attach it right through the uploader on the site. Files should be small enough.

Here are the files. The datalog is just a long run at idle RPM.

Thanks for any help!

that's unlike any other miata out there -- i.e., figure out what you setup incorrectly.

Haha yea, I got that impression from the first few responses and google. I spent about 5 hours fiddling yesterday, so I'm out of ideas. I'm going to try the injector dead time as suggested above.

Also I have two possible engine side issues that I would like opinions on, could these be part of the problem?

1. Before I started tuning, I pulled my injector connectors to check timing without running the car. Two of them broke their clips. I have replacements on the way. I was thinking sitting "still", they would be fine for running idle. Was I mistaken?
2. My timing light doesn't work for shit. It was super sporadic when I was setting timing, and now it wont fire at all. The little amount of time it did work, the timing mark looked very close, but I haven't been able to verify it since. Would a couple degrees make a huge difference in my VE like this?

Okay, so I changes a BUNCH of stuff. Please let me know what you think.

1. Baro correction: None
2. tach out: off (was cuasing a problem with my circuit. I corrected it.)
3. The above caused an issue with my timing light that was corrected. Turns out my timing was 10 degrees too retarded. This made a difference but did not solve my issue. Raised VE by a few percent.
4. Injector dead time: lowered to .9ms with no correction
5. Increased dwell to 7.5 crank and 4.5 nominal
6. Moved spark duration up to 1ms
7. Opened idle screw to leanest position
8. Lowered minimum throttle position.

All of this leaned me out about 1.0-2.0, up to 12AFR after warm up at idle. This was still too rich. So I adjusted my injector input to 300 and 320 cc (even though they are 254) and took data. 320cc got me to my target AFR. Datalopgs attached. Can anyone tell me anything from this data? I am completely out of ideas.

Would my broken injector connector retaining clips cause this issue at idle?

doesn't the '94 use batch (untimed) injection?

turn on "Incorporate AFR target"

turn off secondary fuel load

start there

EDIT: just pulled up the '94 schematic, looks like it can run sequential. That setting may be right.

Thanks! I will try that now. (Spark is wasted/batch, so maybe you were remembering that?)

Any input on my realization right after your reply concerning batch vs semi sequential?

So czar,

I made those changes. See log attached. However, it only went up in AFR (13.9) when my EGo became active. From what I understand, that means my VE is still way off. It reached the maximum adjustment % allowed and wouldnt go any further.

Earlier NA are batch fuel (except for CA). I am away from my CPU, check the info on the number of squirts. I think I saw a 2 there, you may need 1. The deadtime error goes up with more squirts.

Tried 1 squirt per cycle simultaneous. No improvement. Data attached.