Does the ecu use any coldstart fuel enrichment table? Or does it use the fuel maps in open loop at cold start?

I've already fine tuned my idle and cruise trims with the MAF smooting table, raised the min temp for closed loop, which both have improved cold starts, but I still have a lean cold start due to my cam setting.

If someone can(dissasembly gurus) find what the ECU uses for the cold start enrichment it will benefit us Evo8 guys greatly since we can't change cam overlap at idle.

 

This is something I've been wanting to look at for my E85 conversion. I'm not getting anywhere with the deciphering the rear O2 heater OBD-II routine, so maybe I'll start looking at this.

 

That would be great!

 

well, if you've changed your temp for closed loop then you'll be running in open loop until then. Just change the fuel cells (load = 30ish, RPM = 1000ish) to lower your idle AFR. My car is set to always idle in open loop and changes to the fuel map defiantely directly affect my idle AFR. Unless you're having starting problems this will fix your lean idle.

Here's my idle portion:


With my mods/injector scalings/etc that gets me ~13.5AFR at idle. (Richer helps keep my P0300 bug away)

 

I've tried that already...but I will try again. How is your cold start ? My lean idle is only on cold start then it is fine.

I've noticed that if my idle timing is over 9* I get a P0300 at idle.

 

My car idles at 15-15.2, i only have basic bolt ons and recently tuned, i understand if during idle which has no load shouldnt be an issue and wouldnt cause damage? My cold start went 16-17 for a few seconds, can this also cause damage?

 

Won't cause damage, but unless you have forced the car to run in open loop all the time, it shouldn't be idling at 15-15.2. Maybe your wideband is off a bit? Or maybe your fuel trims still need to settle a bit more.

 

I think 3zero is using AEM wideband. As far as I know, LC1 need frequent recalibration, but AEM? I have no clue. He still with stock injector, LTFT is -6 & -3.. should be fine.

 

Rear O2 will have very little to do with any tuning. It is more used as a check for efficiency than anything else, which is why it is not on all cars.

In my rom there is a 2D map for the front O2 sensor as a backup startup delay. An O2 sensor needs to be at operating temperature which is why all modern sensors use an internal heating element that is enabled at low rpm and load. The map has a timer to prevent the closed loop system from trying to make fuel corrections when the sensor is under temp, and it is based on engine temp. There are also other checks the ecu uses first, where it will look for a certain voltage to be reached during the warmup of the sensor and will only rely on the timer if the voltage is not reached.

Mr Fred, I had a quick look at 88590015 and you might want to see if the map at 30be is the same. To scale it, 128 = 60 seconds.

 

mrfred, i am hunting those heaters for a half year now as you know, what I can say there is no OBD check for it in your ROM also, it should be Mode 06 MID/PID 41, but also in your ROM it ends up with MID/PID B. I guess the only way is to track either the P0135, or search within readiness tests.

 

All this winter I've had to deal with rpm going to 2100 at start up. If I start in neutral or gear it jumps to 2100, if I then let out the clutch the rpm drop to the set 1300. If I depress the clutch and tap the accelerator it goes back to 2100, when I let the clutch out it goes back down.

I have tried setting idle with the sas actuator mode in evoscan.
Enrichened the fuel map and raised the closed loop operating temp.

How can I stop this?

 

There is a post start idle step increase map along with a decay map that goes with it. These need adjusting to prevent it going too high.

 

Are these the 2D-Post Primer Enrich and 2D- Post Primer Enrich Decay maps?

 

Just curious, are you using Tephra V5.10 mod?

 

No, they are idle control maps. It appears to be based on air temp.... the same strange x-axis the main 3d stepper table uses.