So I have come to the conclusion that the fuel tables I listed in my 'startup fuel and ISCV tables' thread might not not work in the 3D SD roms. I am heading to Portland,Oregon for the week so I won't be able to test it. If someone wants to log the tables on a MAF tune, then on a 3D SD tune, the first thing they will notice is the IPW while cranking table doesn't seem to do a damn thing in the 3D rom. I get the same IPW while cranking during all temps when logging 2-byte IPW.

-Jamie

 

Maybe it's not jitter, but it looks a lot like this: https://www.evolutionm.net/forums/7321255-post49.html

 

Okay, reading through some of those older threads it looks like it is a severe version of jitter with the IPW dropping out entirely. According to most of those threads, I shouldn't encounter it under most conditions and is related to MAF scaling transitions, as I expected from other SD systems.

Even though it dropped out completely on my logs, it's quite possible that it would have been much more intermittent without the jitter fixes that were already activated. I'm going to go through and test as much as I can before driving around.

Hopefully driving conditions will not result in the RPM/kPa combination that causes the conversion error.

 

This doesn't appear to be the jitter. It appears that the crank/cam signal might have lost signal perhaps. What was your KPA, load and airflow HZ when this happens? The jitter only happens in a lower RPM range than you seem to be seeing, unless the RPM scaling isn't correct in that graph. It almost always happens at a steady throttle and rpm, not accelerating like your logs.

I see you have a 1G DSM. Are you using the 9653 rom or the 9417 rom?

-Jamie

 

I'm using the 9653, as required by the 1g CAS. This was stationary gradual increase in throttle to get a baseline VE at "0" load. I realize the load in the evo is based off of airflow and scaled so it will recognize a negative load (downhill/decel), so this would be neutral load between 8-20.

Looking at the 1byte load, it all corresponds to a slight throttle increase (less than 1%) with load between 14-17. I'm guessing I will never see this load while in gear, so I'll go ahead and try a cruise tune (no boosting) to try out my existing VE.

 

very nice!!

 

Your load is WAY too low. You aren't even on most compensation maps. Cruise load is generally between 40-60 so you have some reading to do. The ECU might be teetering on decel fuel cut at such low loads.

-Jamie

 

Without reading too much above me,,,, you're using 1:1 kpa:load right?

 

I'm pretty sure I have everything set correctly. If you noticed that was at about 10-20 percent throttle and, as stated before, not in gear. This was only to get a base VE before putting a real load on the engine.

EDIT: KPa to load is 1:1.


EDIT: Also, I would like to note that the Accel Enrich seems to be logging a straight value for the output of the SD enrichment? It's right in line with what seems to be the percent throttle. Is it supposed to log the airflow enrichment or something?

 

This is strange. I'm seeing this on a friends car that I'm tuning. I've never seen this until you brought it up. His does this at idle. Have you logged idle?

Jamie,

This is what I have. IPW goes to zero and o2 Feedback goes to 0 at the same time. Bad o2?

At idle
9653 rom:
Coolant: 179*F
KPA: 30-50
Load: 30-45
Air Flow: 40-70 Hz

 

It appears to be losing cam or crank signal to me. It's also acting the same way it does during decel fuel cut. I haven't ever seen that happen at idle before but I never really use the 9653 rom so IDK about any idiosyncrasies it may have.

-Jamie

 

Went for a drive today and pulled a log. I didn't run into the IPW cut anytime while I was actually in gear except on decel. It seems to be just a regular old jitter.

I'll go for another drive and pull a log tomorrow on the way to work. Hopefully any inconsistencies will be solved by just driving around and continuing to tune.

 

So if you use Jamie's logging maf kpa/load..

What do you do about the load differences ? 20 psi is two different loads when you compare sd to maf.. Meaning fuel tables don't line up as well as ign

 

Did you log your VE at WOT on MAF?

-Jamie

 

I haven't put the maf on, I have an old maf rom to start updating I just wanted to see if I can take my sd timing map and put it on the maf rom.

I do remember when I first put the sd rom on my maf timing map was off because I was pulling more load on sd.

VE values effects load correct?

Since I set my fuel map to desired and tuned my ve to yield that..
My ve is 144 in one area.

19-20 psi is 310 load at peak