Steady state throttle is where I notice it the most, it even threw a PO300. That's the first time I've ever seen that code.

I actually increased the asynch vs tps table right from the start after reading one of Johns thread SD threads.

 

Mine is clockwork in that range. It immediately smooths out above or below that RPM and above or below that map. I know the VE tables are good, too, because I can be at that map or RPM and have STFT around 0.

There is obviously something happening in that range that I can't quite figure out just yet. It's weird because both have to be in that range for it to happen.

BTW, I capped the nipples on the TB for the EGR today and it still occurs, so that's one less culprit.

 

Absolutely, I've seen the same thing, above or below that window the car runs just fine.

 

Just another 'spitball', that problem area you describe is really close to open/closed-loop crossover point.

Or does the SD patch have the car run totally open or closed?

 

My Open/Closed loop tables are modified a bit, the values are slightly dropped. It looks like Erics' are stock.

 

I tested full time open loop and it still did it. So, again, that's one less culprit.

It looks like I am eliminating almost everything as the cause...I'll get there eventually.

 

I think I'm going to try playing with the MAF Scaling & smoothing tables & see if that makes a difference, unless it's been tried already.

 

I've already tried that as well. I made the values all identical for both scaling and smoothng in that area and it still did it.

I was going to try the opposite next, which is the 'easy speed density' tuning method where you flatten the SD VE tables and just use maf scaling and smoothing for VE. But, I have a feeling that won't work either.

 

l2r,

I'd like to see a log with the following items:

- RPM
- load
- MAP
- IPW
- 2-byte MAF Hz (FFFF89E2)
- FFFF89AC (2-byte)
- FFFF8F3A (2-byte)

Don't log anything else. It makes your plots way too confusing. And can you label the traces. I'm a bit color blind.

 

I was referring to something that was pointed out in one of the lean spool threads. There was believed to be some additional correction below the lean spool activation point that seemed to be related to lean spool. Some correction that looked like it was meant to smooth the transition into the lean spool AFR mapping.

Somebody brought it up as a possible reason for why a MAF based EVO will want to drop into the low 10s/high 9s under low/mid load and low engine speed under certain conditions.

I'll look for the posts tomorrow on it. I think it was something that the periphery bit for lean spool didn't disable.

 

No problem...will do. I have logged all of those before, except FFFF8F3A. I will add that and get a log today.

FYI, the RPM will be two byte, the map will be two byte, the load will be tephra 1-byte, unless you want something else.


Eric

 

Interesting, let me know what you find. I sort of see the oppostire though, where it looks like the IPW is dropping out (spiking down) and then back up rapidly. But, I would be willing to try anything and get as much info as possible.

 

OK, mrfred, I have these logs for you. 8F3a just looks to be some sort of inverse of 2-byte RPM. I'll post up some screenshots of the logs, but it doesn't look to be anything new just yet. I'll try to zoom in a bit on the curves, since most are very close together. If you want, I will even post the logs in the .dif format that can be read in Excel or LogWorks.


Eric

 

Post up the .dif.

 

OK, here we go...here are some screenshots, followed by the two logs (way to the gym and way home). I have a lot of other things logged, but with DMA, it doesn't matter...just hide those.

This shows the jagged IPW, with the other curves labeled....IPW smooths out once past the 2500 RPM mark:


This shows another area while cruising in the trouble zone:


This shows cruising outside of the trouble zone (map too low), with a smoother IPW:


This shows idle with a nice flat IPW:



Ah crap...the .dif files are too big. Zipped up, they are about 150kb, too big to post. Let me know if you want me to email them to you.

I wonder maybe if this is some sort of misfire, since gear head mentioned he even got a P0300. My plugs are due for a change, but this doesn't happen with the MAF, only SD. I can flash back this weekend to double check again.


Eric