Fast_Freddie

iTrader: (50)

^ So far... I left all the idle settings as the stock V7 settings and readjusted the BISS, I will have to drive around with it for a week or so and see if it pops the code again...

Appauldd

iTrader: (22)

I think if I do that, my car won't run. Revolver cams can't idle down low. I will give it a shot though.

Are you still getting the 2k rev?

Wiznaz

iTrader: (13)

FWIW, I too am seeing poor idle/cold start symptoms. I get CEL P0507 "Idle higher than expected." (2k rpm) I have not checked ignition values but the AFR is all over the place. The car will bog and give me a ~10.3-17.5 AFR if I don't tap the gas to help stabilize it. Also, if I'm cruising and I put the car in neutral to roll towards a stop light, I just get a bouncing idle until the car reaches ~5mph or less. I'm going to upgrade my Tephra and apply this patch. I'm glad I found this thread as it has been annoying the crap out of me! Count me in for further testing.

I have a IX with:

272's
Buschur IM and TB
850cc
EGR block off
3" intake
Tephra v5

Let me know if you'd like to know any additional info.

Fast_Freddie

iTrader: (50)

I haven't really been noticing... like I said before it did that with the 96940011 rom anyway...

SWOLN

iTrader: (6)

I'm just trying to think out loud here. So, I'm thinking that when the system is normal, EGR enabled. The factory set-up retards the timing and leans out the fuel to light off the cat, right? It seems that the load also goes up, but when we disable the EGR, the ECU wants to still place that load, but instead of placing that load it just free revs to that 2k point. Am I missing something? Are we still missing something? Are we overthinking this? Again, just thoughts...

Appauldd

iTrader: (22)

You are correct except for the load. It really does not change much at idle. (at least mine doesn't)

MAF Hz does change quite a bit....the 2k rev causes my MAF Hz to go from 35ish up to about 70 or so. So if MAF hz is a factor for calculating Load then I can see where your hypothesis is correct. Albeit a very small change in load.

Here is my thoughts.....The rev is the result of the ECU trying to utilize the EGR for rapidly warming the engine. Because the EGR cannot recirculate warm unburnt/burnt gasses back into the engine a rich condition results. Thus the engine revs. As the ECU makes note of the rich condition and leans it back out, the rev returns to normal idle RPM.

We have a timing table for warmup which leads me to assume there is a fuel table as well. We have yet to discover it though.

I am simply shooting from the hip on this one though. In my feeble attempts to understand the ECU it seems that the more I understand the less I know.

I have come to realize that 03 and 04 VIIIs will have several tables different from 05 VIIIs. We cannot have "universal settings" especially in the realms of idle stepper tables and ISCV tables. Even the factory tune isn't the same from year to year.

Not all ROM's are created equal. Our v7 sets the foundation for the ROM but we must tune it differently for the year of our cars.

Fast_Freddie

iTrader: (50)

I agree with 99% of this statement... and deep down in my heart I believe there is a low coolant temp fuel trim map...

Appauldd

iTrader: (22)

So what is the 1% that you don't ? ? : )

Fast_Freddie

iTrader: (50)

The more I learn about the stock ECU the closer I get to ironing out all the tiny glitches that drive me crazy

Appauldd

iTrader: (22)

Yeah, this thing will drive you nucking futs if you let it.

On other news....I am putting the car in winter mode this weekend. Hopefully time will allot me the opportunity to test some cold tune parameters. I want to get rid of the p0505.

95630706

OK. So I have an 03' that runs Phenom's modded 96530706 with just cut+pasting in my maps flawlessly, but on Phenoms's 96531706 (SD) I have the cold start driveabillity issues described in this thread.

For example: If I try and drive it before its warmed up it will lean out and buck/ die when the throttle is opened. After it's warm i't drives just fine. (GM IAT wired to the fuel temp pin + 3barMAP)

At first I assumed it was SD/ VE / tuning related, but after reading this thread I'm starting to wonder. If it was a VE calibration issue why would it improve or go away when the car was warmed up?

Differences in the way these two 9653000 ROMS are set up might be a good place to look.

Appauldd

iTrader: (22)

There is a setting somewhere that we have yet to discover that causes the issue. We are all trying to find it.

95630706

Ya. I read that part. I thought that the fact that these two ROMS that are essentialy the same, less SD and set up by Phenom, but one does it and one doesn't do it on the same car might be helpful in the search.

I don't know how many people have run these two ROMS back to back on the same car that would notice.

Appauldd

iTrader: (22)

Both roms exibit the same cold characteristics with the EGR and EVAP stuff removed. Certainly there is a periphery that causes the issues. Problem is that once this stuff is out of the car we have to disable the bits.

The only way we will be able to not have cold rev issues (which isn't really an issue at all) is to have a patch like the EGR disable for the EVAP. Then we wouldn't have to worry about disabeling a periphery bit that could be the cause of the cold rev.

95630706

Same car, same hardware set up (EGR/ EVAP intact). Two V7 9653000 ROMS both with EGR/EVAP turned off. Yet only one produces the cold drivability issues.

I feel like I keep saying the same thing over and over, sorry, just trying to draw attention to this as a possible lead.

At least in my case logically the "problem setting" should cleary be the point of difference in these two ROMs with all the other variables he same.