does anyone know about rom tuning the factory ecu

[3SVERIZON]

i was just wanting to know if anyone knows some information on rom tuning the stock toyota ecu

[ChrisD]

edit

[alltracman78]

Might as well get a ems......
Almost the same price.

[GMan]

Formerly known as G-Force.

If you paln to stay relatively stock a retuned ECU is a
good upgrade. If you plan Major upgrades a full
ems is the way to go.

I have a retined ECU and it ha srun very well with just a
basic common tune. Would help a lot ot have
it tuned in a dyno. Just have to find a tuner.

Regards;

[Plex]

Are our ECU's self learning like the 4AG ones? I assume yes. That was probably a dumb question.. anyway, I've heard that stock 'tuned' ECU's for 4AG's re-learn themselves so you lose the tuning eventually.. anyone care to confirm or tell me to stfu?

[GMan]

If i understand your quesion, this is the answer.

Under light load, no boost, the ECU uses the O2 sensor
to determine fueling. There is not not much you can
do to change that. With black boxes, after market fueling
controllers, all the changes up made Are countered by the ecu.
Tuning a new chip may make a difference, but would not change until re-reprogrammed. It only aims for target A/F ratios.

Under boost or high load, the ecu switches to open loop
and adjusts fueling by maps, so no contol is exerted by the ECU.
Just predetermined fuel and timing points. This is where black
boxes can make a difference.

The ECU does not self "learn" per say.
Not familair with the 4AG, but it is probably similar to ours.

Regards;

[Colin T]

You're probably thinking of the "Freedom" ECU. It's an ecu developed in Japan that basically "Reads" what the car is doing, and adjusts fuel maps, ignition curves, everything automatically.

[Plex]

No.. I wasn't thinking of the Freedom ECU..

I think they might have SOME self learning capability.. because it'll adjust how much fuel to use based upon what octane gas you use..
For example, when i forst got my car, it had 'regular' gas in it (rod knock anyone?) so when i filled it up I ran premium (92 is the best we have here) and I got 175 miles for the TANK, without driving hard at all.

After that tank, I filled her up with Premium again and got 300 miles for that tank. And have gotten 300 ever since (roughly, give or take 15 miles)



Maybe it only can 'learn' certain things? I dunno *shrug*

[furpo]

i have been looking into building an interface to allow the use of and eerom in place of the factory rom and have all but decided it is not worth the effort. toyota build the ecu with the rom as an integral part of the cpu board so it is allmost imposable to replace. companies mentioned above have figured out a way around this but the that leave you with no option but to use them again for retuning if you are going to do future mods and also you have to use the afm (depatable if this is a draw back or not).

i have seen examples of aftermarket ecus when tuned right that drive better, deliver more power and torque with better fuel milage than the stock ecu and leave the option of being retuned if future mods are done.

roger