Evoryder

iTrader: (55)

No go, still spiked to 2k...actually drove a little worse at low speeds.

Appauldd

iTrader: (22)

I got the 2K rev today. Once the car is warm...the rev never returned though. It acts like it is trying to find its idle by reving up to 2k then slowly back down to its setting.

When I set those ISCV settings, I had to re-adjust the BIS.

evonut270

have you tried raising the temp required to hit closed loop?iv had a few cars with similar cold start problems that iv cured this way.

Appauldd

iTrader: (22)

What did you raise the temp to?

evonut270

between 60-70 degrees.stock if i remember is either 0 or 20

Fast_Freddie

iTrader: (50)

Yeah stock setting is 32* F

fostytou

iTrader: (15)

Those tables don't do what you think they do...
https://www.evolutionm.net/forums/7634241-post69.html

SWOLN

iTrader: (6)

Hey Paul,

Got the new settings in finally, it works fantastic so far. Thank you! I have the 2K spike in the morning, much better than the terrible stumbling that I'm used to.

scheides

iTrader: (10)

I've been playing catch-up on this thread; has anyone found the root cause of the 2k-3k rpm spike on cold startup? It's SO annoying.

My car also has and idle problem during warm driving that I'm trying to get to the bottom of. First gear, medium acceleration, push clutch in and coast, rpms fall to ~500rpm, timing is at ~5° and then finally it catches itself and pulls back up to ~1000rpm idle. My biss screw seems frozen so I'm wondering if this is actually a hardware problem.

I went through and have enabled/disabled tons of settings, FAA bit 11 and the rest in that list. Got rid of my hole of -5's and tried several mixes of the cold timing % table before that. Does anyone know definitively what FAA Bit 10 (Timing Knockdown on Light Acceleration and less than <3000) actually does?

My car has been doing these little things for a long time, and I don't recall when. This thread has given me inspiration to try and solve all the 'little' problems. I've even switched to open loop idle, nothing seems to actually make problems go away...it may get better for one warmup cycle, get my hopes up, and then just return the next time. Very frustrating.

Fast_Freddie

iTrader: (50)

The one thing that I changed that actually changed the 3000 RPM spike warm-up was zeroing out the percent low coolant temp timing trim, after I had already changed the hole of -5s and had been driving around like that for a week. For some reason it made my problems go away...

Scheides, I would suggest trying my settings since we both have 05's... just a suggestion...

D-VO

iTrader: (1)

I'm wondering in what postion your BISS is stuck at. I had the same problem when my BISS was set too high. Turning it down did solve the problem. As far as the idle drop, how big are your intercooler pipes? I've been haivng a customer come back to me several times complaining about his idle dropping to 500RPM and even shutting off in some instances, but he's the only one who's car I'm still having difficulty getting correct, and also the only one who has 2.75in intercooler pipes. I've already tried tuning the MAF comp but to no avail. Yesterday I cleaned out his ISCV, BISS, and throttle body and it stopped shutting off, but the drop to 500RPM was still apparent.


Do you think it would make a differeance if all these 'Desired ISCV' tables were set to the same values?

Appauldd

iTrader: (22)

Frosty....please enlighten us with your knowlege of the ISCV tables then.

I ask becasue most certainly when I raised the values in the AC on ISCV table my stalling condition ceased.

logic

iTrader: (2)

At this point, my cold start and cold idle are damn near perfect, even with E-85 and no EGR: the car fires on the first crank, no high-RPM warmup idle, no stalling post-cranking. My settings are basically the list that Fast_Freddie posted, minus the idle RPM changes and closed-loop trim control adjustments.

I still have a nasty low-throttle stumble during warmup, which I suspect is EGR-related; it has smoothed it out significantly from where I started (suggesting the other problems were simply aggravating it), but now I just need to spend a bit of time logging cold starts/drives.

----

scheides: looking at the code that checks FAA bit 10 (in 96530006, it looks like the code for that is at sub_17D62), I see a bunch of threshold tests. A flag (FFFF8A18 bit 0) is set if all of the following are true:

• RPM is between 3500 and 0 RPM (words at 17F6 and 17F8)
• coolant temp > 167F (word_19FA)
• vehicle speed frequency > 10Hz (word_19FA)
• a few bits in various locations in memory
• FFFF8A56 is between 0x178C and 0x16A (words at 17FA and 17FC); this is boost-related, but my disassembly is incomplete here. Someone want to fill me in?
• load error < 1.56 (word_24AC)
• vehicle is moving (speed > 6mph) (word_2C5C)

Basically, if you're up to operating temperature, in motion, and your load error isn't way out of line, it sets the flag. I haven't traced the use of that flag yet, but I'd suspect there's a timing retard associated with it, as the wiki entry for that periphery value suggests.

I'm running out of time right now to look at this, right now, but maybe this is enough for someone else to dig through it if they're motivated enough?

Fast_Freddie

iTrader: (50)

Logic I take it you are using Mrfred's egr routine... I know dumb question...

logic

iTrader: (2)

Yep, I've disabled the EGR via the toggle at 103D.