just so were clear and this doesn't confuse anyone else..

The actual ROM isn't the operating system. The real time operating system would be embedded onto the ecu making the ecu an embedded system.

when you flash the rom to the ecu it goes to a flash chip, which is then read from the rest of the system.

So in reality it wouldn't be wrong to call each ROM a firmware version, since each runs on the same platform, but are slightly different.

standard memory map in a flashchip uses image banks, bootloader, nonvol, and dynamic nonvol.

id like to know as much as i can about the stock ecu as its interesting to know the in and outs of what you're working with.

 

I'm not a fan of putting ROMs from another ecu in, this often causes it's own issues. another option would have been to reduce how much the ecu can trim the fuel at idle, that way it doesn't swing wildly rich then overcompensate and swing wildly lean.

However, all of this is a band-aid fix for your real issue which is something else altogether and likely mechanical.

 

the 9417 rom is one of the best roms you can use for 03-04 evos. The only other option would be the 9653 universal rom, which sucks on most ecu's cept for 05 evo.

 

Alright, I have HKS 272s, and my car idles like dog crap, and there are cars with much more aggressive cams out there idling way better. With that said, could you please elaborate a little on the second suggestion you made? My open loop load is currently at 86.9 @ 500, 1000, and 90.0 @ 1500. Id like to try the first method, but which ever would work the prettiest so to speak. any help is muuucchhh appreciated. Also, my symtoms seem to be very similar to the OP.

 

lol hks cams are really mild. how much timing do you have at the top left corner of your timing map? and whats the car idling at rpm wise? and what air intake?

 

You are absolutely correct Chris, my cams have mechanically removed all usefull vacuum to make the DV function properly. This in addition to not having an IAC system compunds it. v7 however might help by allowing access to areas not available before and it already has to some extent. more work cut out though

 

I agree, no reason the HKS cams can't idle smooth as butta.