Poor Cold Idle (Yes I searched)

[Appauldd]

I searched for hours trying to find a conclusive answer as to how to fix cold idle issues. No one seems to have an exact answer.

Here is what seems to be happening....
Timing seems to be pulled so much that AFR goes way lean....21ish

I have zeroed out the warm up table....to no avail.

The car will drive, but bogs horribly below 2300 rpm. If I rev it higher, I can drive, but between shifts at low speed as I leave my sub division, it will run super lean.

I realize I should let the car warm up completely then drive. Sometimes, poor planning on my part means I have to drive my car while it is still cold.

Once the car is warm....these issues are completely gone.

Any conclusive ideas???


As people have requested I am editing the original post with the changes we found that solve cold idle and cold cruise conditions. Thanks to all who are dilligent about solving the problem....you know who you are.

Even with these changes the car will have a brief 2K rpm rev that will settle within a few seconds. (issue being worked)

I have no EGR junk or EVAP junk in the car either. It idles smooth and holds exactly what my Idle tables state. It no longer goes lean when attempting to drive with the engine cold.

These are my settings....and should work well for 03 and 04 VIIIs

Table
EGR System Enable/Disable....changed from 1 to 0

Periphery FAA bit 11 (Disable EGR . Enable Ign Adv) set to stock setting = 0
Periphery FAA bit 10 (Timing Knockdown on Light Acceleration and less than <3000) set to = 0
Periphery FAA bit 9 (enable warmup ign retard) set to stock setting = 1

Periphery FCA bit 15 (P0443, P0446, P0403, P0243, P0090, P2263) set to = 0
Periphery FCA bit 14 (P0450, P0451, P0452, P0453 Evap) set to = 0
Periphery FCA bit 13 (P0441, P0442 Evap) set to = 0
Periphery FCA bit 10 (P1400 MAP sensor) set to = 0
Periphery FCA bit 9 (P0401 EGR Test) set to = 0

Periphery FEA bit 14 (P0069 MAP vs Baro) set to stock setting = 1

These are all that pertain to EVAP, EGR and cold idle issues.

Post Primer tables set to match 9417xxxx

ALSO....

This table....for v7 96500006 versions...

<table name="Ignition Unknown Map (warm-up?)" category="Timing" address="61c9" type="3D" swapxy="true" scaling="Timing">
<table name="Load" address="6910" type="X Axis" elements="19" scaling="Load"/>
<table name ="RPM" address="68de" type="Y Axis" elements="20" scaling="RPM"/>
</table>

This will show up as a timing table with a big hole in the cold cruise area.

All I did was change the stock +5* timing areas in the idle area to my current cam timing setting of +11*. I left the hole alone other than changing the +5s to +11. It seemed to help idle considerably....the car idles much smoother and timing does not fluctuate near as much as it used to.



Fast Freddie settings....should work well for 05 VIIIs

*Percent Low Temp Timing Trim vs Coolant Temp- all columns set to 0%
*Ignition Unknown Map (Warm-up?) (AKA the Hole of 5's)- set to match high octane timing map
*Startup IPW Latency msec- Matched the 14v Injector latency value
*Closed Loop Long Term Trim Control- set Low to Mid- 62.50 Mid to Low- 50
*Open Loop Load #1 & #2- set to match the 96940011 rom
*Open Loop Throttle #1 & #2- Set to match the 96940011 rom
*Desired Idle RPM Neutral- 171* & 180* set to 1000 RPM
*Desired Idle RPM Drive- Set all columns to 1000 RPM
*Desired Idle RPM A/C On- Both Neutral set to 1117 RPM, Both drive set to 1000 RPM
*EGR System Enable/Disable- set to 0 (not FAA Bit 11, but MrFreds EGR Disable routine)
*F9A Bit 2 set to 1 (the rest are zeros)
*FAA Bit 1,3,4,6,7,9,12,14 set to 1 (the rest are zeros)
*FBA Bit 3 set to 1 (the rest are zeros)
*FCA Bit 0,1,2,3,4,6,7,8,11 set to 1 (the rest are zeros)
*FDA Bit 4,7,9,14 set to 1 (the rest set to zero)
*FEA all bits set to zero

***Notes***
*Before doing anything, you need to adjust the BISS as the base idle settings are different in the V7
*FAA Bit 9 (Enable Warmup Ign Retard) will change your fuel trims by approx. 8% when set to zero as seen on my car...
*Percent Low Temp Timing Trim vs Coolant Temp- When this was at the stock setting my car would jump up the idle to about 3000 RPM, therefore I zero'd the columns out and now it starts up jumps to about 1500 RPM and slowly steps down to target idle.
*Closed Loop Long Term Trim Control- In the EDM rom these are fairly high compared to the 96940011 rom so I lowered them to suit my Idle & Cruise Hz readings.
*Open loop load and throttle. I matched these to the 96940011 rom because these are the open loop switchover points and I didn't wanna retune my map as much.

[lan_evo_mr9]

I had the same issue- I disabled the EGR in periphery bits, zeroed out EGR table, and I also noticed that my IAT scaling was off. Don't know if that will help you or not, it worked for me though. Good luck

[nothere]

have you lowered those cells in your fuel map?

as long as you are warming up you should be in open loop

I realize this is not a proper fix.

[Appauldd]

My EGR stuff is all disabled and zeroed out. Please explain about the IAT scaling...I havn't seen this before.

Fuel maps are 14.7 for start up and cruise cells.

The car starts great....cranks for like one second and fires right up.

[nothere]

but your closed loop cells could be blocked sevens, it wouldn't matter- except when you are in warm up mode.

[Appauldd]

Originally Posted by nothere

but your closed loop cells could be blocked sevens, it wouldn't matter- except when you are in warm up mode.

Closed loop cells?????

The only 7s in my timing map are out in the pull areas. My idle areas are 11s.

My car is quite modded....If it matters.
FP Green (ported)
Revolver cams, springs and retainers (0,0)
Ported head
Ported ex mani, O2, and hotside
Cobb exhaust (catless)
HKS DLI II
HKS suction, upper and lower intake pipes
Vibrant filter
Mishimoto FMIC

[lan_evo_mr9]

The IAT scaling was a snafu on my part....When I changed ROMs, I forgot to even look at IAT scaling. I loaded up a buddy's rom (same as mine) and noticed that I forgot to change it. The temp scaling and egr stuff is all I've done. Very little change to ISC stepper table also. That may help too.

Edit: On the ISC stepper table I just raised the colder temp columns at most 3-5 units and tapered from there. I also raised my closed loop temp table to 30 C.

[nothere]

closed loop fuel cells - all the 14.7 you see.

those 14.7 are a facade. make them sevens if you want, OR change the warm up area to a lower number

[biggie5252]

Disabling the EGR bit will cause cold idle problems. If you reenable the bit, I bet it goes away.

[nonschlont]

do you have FAA bit 11 disabled? I tried disabling it, but idled like poop, and enabled it back immediately. I didnt disable the other 2 bits...

[rolly1818]

similar problem, when i am warming up car idles lean around 15.5 to 16 on the WB.

after i warm up car is fine. i can actually drive pretty well during warm up, i think i disabled the warm - up ign retard.

also, i dont think JDMs hve the EGR hardware, etc.

what do you think?

[fostytou]

Try re-tuning with lower injector latency (Just cross-posting this here for anyone stumbling on this thread). Solved my problem after hard pipe install.

[rolly1818]

forgot to mention i am on SD, i am pretty sure that has an effect...

[Appauldd]

My injectors are scaled to allow me to have LTFT low of -1.03 and LTFT mid of -0.99. I don't think that they can get any better.

I think there is a table that is used for cold warm up that retards the timing until the cat is warmed.

[EVOIXreno]

Originally Posted by Appauldd

My injectors are scaled to allow me to have LTFT low of -1.03 and LTFT mid of -0.99. I don't think that they can get any better.

I think there is a table that is used for cold warm up that retards the timing until the cat is warmed.

Sometimes the trims might be ok but that doesn't mean they are scaled correctly.