Evo 8 ECU In 2g Works!!

[the_mork]

I've always preferred using the throttle switch for map switching but you can't do that if you also want valet mode. It just seems simpler and cleaner to me.

 

[williillii]

Yeah that will do it also, glad you guys resolved the issue. Looks like ill be picking up an omnipower 4 bar since i've more than maxed what my gm 3 bar can read running 30+psi. Im also in the middle of building my own map switching harness for dual maps anyone else on here make one of these?

Have you had that problem before? Do you know why the MAF plug needed to be grounded for us to get a good MAP signal? Or am I just crazy? I dont see how that would affect it. Unless the MAP grounds out through the MAF ground?

 

[Dragon34x]

Hey guys, I'm in need of some help... I'm using a 3g 2003 GS ecu to do my conversion and I'm having issues connecting to the ecu. I've followed the pinout guides here and those that are available for the 03 3g GS ecu. Evo/eclipse pinouts are near identical with the exception of a few additional sensor pins.

To begin with, the car i have doesn't have the prettiest wiring setup... The previous owner installed a aftermarket immobilizer, a SAFC, and a turbo timer. I believe the SAFC is drawing power from pin 25 and grounded on pin 26. Anyone here think that having the SAFC powered/grounded on these two pins is causing power issues to the ecu? Most of you are probably wondering why I haven't completely removed the SAFC so to answer that question, i'm keeping it connected as a "just incase" i can't get the evo/3g ecu swap to work for me.

I also just now removed the immobilizer that was installed, it kinda helped. When the immobilzer was in ecuflash wouldn't see the ecu than it would... basically on/off not a solid ecu is on. It also allowed me to clean up part of the wiring mess atleast

Also, I'm doing this on a 96 GS-T... Any Ideas/suggestions would be much appreciated. Thanks

Edit: Forgot to mention that I also tried using Evoscan to see if i could connect to the ecu that way and i received a message that said "sync bit error"

 

[Gus@RRE]

I've always preferred using the throttle switch for map switching but you can't do that if you also want valet mode. It just seems simpler and cleaner to me.

I like the throttle switch but since im using a pressure switch activate the map switching in conjuction with a meth setup i had to go the map switching harness route.

Have you had that problem before? Do you know why the MAF plug needed to be grounded for us to get a good MAP signal? Or am I just crazy? I dont see how that would affect it. Unless the MAP grounds out through the MAF ground?

I'm a bit confused, it though you said the ground on the map sensor was bad not the maf plug. Not sure why you would have to ground the maf plug since you aren't using any of that stuff anymore. You are using the MDP input at the ecu for the map sensor right?

 

[williillii]

Sorry Gus that was unclear. The map sensor was reading funny on both SD roms and MAF roms. As soon as the boost gauge hit 0psi the MAP sensor would read 10-11psi. So I switched it to a MAF rom just to see if the car would run. We had no signal from the MAF sensor, so we probed around and found a break in the ground. After it was fixed, we fired the car up and the MAP sensor was reading perfectly.

That didnt make sense to me, unless either it was a coincidence or the stock MDP circuit and the MAFs ground through the same wire or something. And yes, factory MDP circuit for the MAP.

 

[Gus@RRE]

Sorry Gus that was unclear. The map sensor was reading funny on both SD roms and MAF roms. As soon as the boost gauge hit 0psi the MAP sensor would read 10-11psi. So I switched it to a MAF rom just to see if the car would run. We had no signal from the MAF sensor, so we probed around and found a break in the ground. After it was fixed, we fired the car up and the MAP sensor was reading perfectly.

That didnt make sense to me, unless either it was a coincidence or the stock MDP circuit and the MAFs ground through the same wire or something. And yes, factory MDP circuit for the MAP.

Haven't checked the forum in a while!

As far as the MDP sensor and maf sharing the same ground it is quite possible. however I don't have a wiring diagram in front of me to confirm this at the moment.

 

[97gst_spyder]

Haven't checked the forum in a while!

As far as the MDP sensor and maf sharing the same ground it is quite possible. however I don't have a wiring diagram in front of me to confirm this at the moment.

Here's another twist. The MAP was all over the place, but the MAF was working fine when I first got everything running. A month later the headgasket extravaganza took place. After that the MAF was inop, and the MAP was all over the place. Once we found the MAF ground went nowhere. We grounded it to the firewall. Everything works fine now.

 

[97gst_spyder]

To get the AC working is there any other pin swaps except the pin 22 into 8?

 

[Silver2GST]

I have not been able to get the AC to work yet ... let me know if you figure something out. I plan on trying to get it to work before this summer!

 

[knochgoon24]

I never had problems with the A/C. Did you follow the pinout thing I scanned back in and posted?

 

[the_mork]

Mine also works flawlessly with just the normal pin changes.

 

[Silver2GST]

I never had problems with the A/C. Did you follow the pinout thing I scanned back in and posted?

Yes, of course! (I did make those ya know )

Mine also works flawlessly with just the normal pin changes.

Good to hear. Then it is just an issue with the other AC circuits I swapped the ECU over the winter (some years back) and when the compressor didn't turn on that summer, I suspected the swap. But it sounds like that is not an issue!

 

[97gst_spyder]

Yes I followed every step! It was a stuck ac compressor relay... All working now!

 

[97gst_spyder]

Mike96, did you ever test the AC 12volt thing? I'm having a horrible issue with AC. When its on, it seems to be loading the engine way way to much. To the point of the rpms drop 3 times faster than normal and if I let the rpms drop from 3k for instance, I'll either stall or drop to 200-150rpms, and bounce to 1500 then back to 600ish.

Without the AC on, my car idles fine and has no issues.

 

[mike96]

No I haven't had a chance to mess with that much. My car has been out of commission for over a year and a half and I just recently got it running. Still not drivable yet I need a rear drive shaft and I need to do something different with the exhaust but I hope to have those issues resolved soon.

 

[williillii]

How are you guys setting your fans up? Ive swapped 3 cars to this ECU and none of them will turn the fans on.

 

[knochgoon24]

I set mine up just like that pinout.

I also set the duty cycle for the fans to either 100 or 0.

 

[the_mork]

Same here. My fans work fine for both cooling and air conditioning.

I did later change my fan settings for 100% or 0 because our fans don't have variable settings based on PWM like the evos do but this isn't necessary for the fans to function normally and wasn't even something that was brought up or solved until we'd been using these ecus for probably about a year.

 

[Hortanica]

So im gonna bump this thread...

I just did the SD conversion on the 9653 rom, and i copied over all my settings that the one thread said to...like, the MAF Size.

What are you guys using for the maf size/settings? Mine were setup in my old rom for the 2g MAF, should i just leave them at the stock EVO Settings? I assume yes...but since im not near the car to try it...ill ask and try to get it setup first.

 

[the_mork]

Do whatever you like in that regard. I'm using evo8 MAF settings but the car doesn't actually care since you are in effect simulating an MAF it just means your settings elsewhere will be different.

 

[Hortanica]

Do whatever you like in that regard. I'm using evo8 MAF settings but the car doesn't actually care since you are in effect simulating an MAF it just means your settings elsewhere will be different.

ok, I guess that makes sense. I'm gonna change everything over to the evo8 maf settings, since it will make it a little easier to compare my final settings with other people's on the forums.


While I'm in here though, asking kind of dumb questions - how bad is it with the elevation changes? I'm asking because, when i get the car tuned, I'm going to be driving it 1200 miles south. The final elevation is the same as the origin, however - im going to be driving through the mountains with a 500-1000' elevation changes for hundreds of miles. Do you see that causing a problem, or should I be 'ok' since im just cruising through?

 

[Silver2GST]

I am not sure how MAF_SIZE is used with the SD roms, but it has a major role to play when calculating LOAD. If you use the dsm maf size (~260) in the EVO rom, it throws your LOAD off (in my experiance, anyways).

One would think that it would make sense to change this setting, but I found this is not the case. You should leave it at the Evo MAF_SIZE setting.

Example: with the DSM MAF_SIZE setting, at 21 PIS I was only hitting ~200 load. This is NOT correct and this setting presents too much timing advance for the TRUE amount of load the engine was under (which should have been much closer to ~230).

MAF_SIZE, in one sense, determines how fast your travel horizontally on the LOAD-RPM tables.

If you do decide to change the MAF_SIZE, please observe your load. Compare your setup to others and determin if your LOAD (use 1-byte or 2-byte load) is in the correct range for your setup.

 

[the_mork]

That is the basic idea of how it works, but you can/need to fix this when changing MAF size by adjusting the MAP sensor VE vs Load calibration so that you match load to approximately what you need. Or, you can make load linear and then build timing and fuel tables from scratch so long as you are aware of approximate airflow and engine conditions.

 

[Hortanica]

Or, you can make load linear and then build timing and fuel tables from scratch so long as you are aware of approximate airflow and engine conditions.

That's kind of what I planned on doing, since I'm gonna be starting with a fresh tune. From what I've read, people only really tune the sd tables to keep their existing tune in check, right? Thanks a lot for the help...I'm pretty sure I've blown one engine b/c of this...so I figured it was time I asked

 

[the_mork]

Unless you are running a giant amount of airflow then I would suggest avoiding that method honestly. A linear load to MAP pressure setup requires a lot of tuning and requires that you're pretty good at it whereas matching the MAP/load settings to a stock fuel map will put your car close to a stock tune to start with and is much easier IMO.