Hi All!

Prepare yourself for a slew of noob questions! Just bought a previously tuned USDM Evo IX and the tune looks to have been obfuscated. The ROM ID at 0xF52 is set to 99 99 99 99. After updating those values to 88 59 07 15 (Tephra) values magically appear and look to be correct! I'm hoping someone can help me answer the following:

1. Can someone tell me if this tune is for an EGR delete?

• Currently the car is throwing a P0401: Insufficient EGR Flow
• At one point the car had an EGR delete installed and then later a new EGR system was put back on (currently still on the car), I'm not sure why it was reinstalled or if the car had the EGR delete when it was tuned

2. Is there a way to know if it was tuned via MAF or Speed Density?

• I know the car is equipped with an Omni 4 bar MAP sensor, does this mean it's been set up to tune via speed density?

3. AFR reads 10 -11 when cold starting, is this a problem? Once the car is warm the idle is 14.2-14.7

4. How can I know that I changed the Internal ID to the correct value?

• The previous owner mentioned that it was set up to no-lift-shift (a tephra feature) and the tephra options look to be correct in the ROM, just not sure. Changing the 99 99 99 99 to other EVO IX Rom IDs also appear to show valid values

Thanks so much for helping me answer these questions!

 

1: Your "EGR System Enable/Disabled" is set to 0 which means it's Disabled. Your Periphery0 FAA bit. 11 EGR Test is enabled "1". Your Periphery2 FCA bit. 9 P0401 EGR Tests is enabled "1" and it's probably where you are getting your code.

2: 88590715 is for a MAF Evo 9. If you want speed density, you're going to need 88591715 and install an intake air temperature sensor to go along with your OMNI. The OMNI helps you record boost over the factory sensor limits.

3: Yes, this is bad. I am fighting the same problem as you are. The car is running on certain tables/settings in the program before the car/o2 sensor warms up and is enabled. Once it is warmed up, the ecu takes over and starts to read the o2 sensor and adjusts itself within the limits of the fuel trims. Fighting the cold start richness can be a pain. It is a balance of High Octane Ignition Map timing of the main map or alt map depending, Idle Air Control Valve ISCV settings and start up fuel. The best way to battle this is 1. Boost leak check and correct any leaks. If you don't do this and you have a leak, you'll be chasing your tail. 2. Ensure your fuel trims are in line. This is adjusting your Injector Battery Voltage Latency Compensation and Injector Size Scaling if they aren't correct. 3. Adjust your BISS if needed. 4. Then you'll have to play around with your fuel tables, ISCV tables and your timing to see what your setup likes. Since you're trying to correct a problem before the car warms up, it will take you many attempts because every time you start the car, it's going to warm up. In my opinion, your timing looks a little high in the idle areas and could be driving your MAF hz up higher and thus adding more fuel. I wanted to test this idea on my car because I am having the same rich cold start problem but at the moment my car is being shipped to another country. Having a log of your cold start would help out to see what is going on.

4. Your NLTS is enabled in the Options, your drop is 800 rpm, I'd change that to 500. Your threshold is at 98% and 150 Load, anything under and it will not engage, make sure you are getting 100% by logging your TPS and ensure your top clutch switch is working/hooked up.

I don't mess with the internal ID. Just leave it stock/what Tephra has put in. 88,59,07,15. There are threads out there you can read up on if you're curious.

I'm no expert myself, just been reading up on a lot lately. If you feel you're in over your head or worried about damaging your vehicle, please pay a professional.

 

Thanks so much for your response!

To clarify, when I read the ROM for the first time, ecuflash displayed an 'UNKNOWN ROM' message because a previous tuner changed the internal ID to 99, 99, 99, 99. This leaves me having to guess what the correct internal id could be. I spoke with the original owner and he confirmed that the car was tuned with speed density so I'm guessing the correct id is 88591715.

Some additional context: I'm seeing some oil pooling on top of the pistons. Engine was built ~15k miles ago. Builder asserts that rings aren't seating properly because of an 'excessive rich condition' on cold start. Do you think fixing this rich cold start could alleviate the burning oil? Or am I well passed that?

 

Ahh I see what you mean by the ID thing. I've never changed that before so I had to do some research myself. I changed the ECU id to 88,59,17,15, saved then reopened it as 88591715 which showed all the SD tables. Cool, I learned something new today. I honestly don't know anything about SD other than an IAT needing to be installed in the piping/intake manifold. But when compared to the stock Tephra map, the one you posted has changes made to it in some of the SD tables.

As for the oil on top of the pistons. Are you sure it's oil on top of the piston and not fuel? Is there a big blue cloud coming out of your tail pipe on startup? Is it hard to start? Are you seeing excessive oil loss in between oil changes? Are you fouling plugs? I would log your cold start and post it because it's kind of a guessing game. When you get down into the 10s AFRs you get bore wash and can damage your rings. It would probably also cause scaring on the walls of the cylinders. I change my oil every 1K miles. I don't drive it that often but I can smell the fuel in my oil. I've been trying to fix my cold start issue since the beginning of the winter.

Also, I know my rich cold start is tune related because my MAF hz is way too high causing problems. When mine is cold my AFRs bounce at 10.5-11.9. No matter how much fuel I take off of the start up, it does nothing. But when I disconnect the waste gate arm off my turbo, it lowers my MAF hz from 120hz down to 50hz and it idles at 14.5-15.3 smoothly. I need to see if lowering my timing will lower the MAF hz. But I wont know until I get my car back in 2 months. Your timing looked high like mine is compared to stock.

If you could log a cold start and post it, it may help out.

 

All very good questions. I actually created a separate post outlining the issue here:

https://www.evolutionm.net/forums/ev...ng-piston.html

I haven't used evoscan yet but need to figure that out. Are there certain metrics I would need to define in evoscan for a good cold start log? How can an engine require a rebuild after only 15k miles??

 

Evoscan is pretty straight forward. Select each item and read the description of what it does. One or two of them need to be in a certain order for it to calculate/read correctly. But move all the ones you want to use higher up on the list, click and drag, this way when you are doing your log, in the spreadsheet all the active numbers will be near each bother and not spread out. Makes looking at it easier with less editing. Don't just select everything because it slows down the readings. Just make sure you have the necessary ones selected. Make sure you select select either Fahrenheit or Celsius depending on your xml and ensure your 2byte to 1 byte load factor is set to 1.5 because stock I believe is 1.2 and your rom is at 1.5. And you may have to add/edit your boost MAP category because you're running the OMNI 4 bar, "Request 38, Function .02369*x-14.2 " The 14.2 is the correction for elevation so you may need to read up on what SLC is set for.

I use, Throttle Position, Target Idle RPM, Engine RPM, Timing Advance, all of the Fuel Trims, Coolant Temp, Battery Level, Load 1 byte, Air Flow Hz, Knock sum, Oxygen Sensor, ISC Steps, ISCV demand, Omni 4 bar or BOOST, Exeternal Wideband A/F ratio, Wastegate Duty Cycle, WGDC Correction, Injector Pluse With, Injector Duty %, Air Temp, and Speed if I am doing pulls and trying to smooth out things. With you being on Speed Density, there might be one or two more that you may need but I don't know about SD.

This should help you get started.