What is different between an AE92 GT-S 1988 4AGE (89661-12320) and an MR2 AW11 85-86 (89661-17020) ECU. I want to know because I ran both ECU on my AE92 without problem, so what's the difference?

Thank you

I've asked this question in the past. I'd like to know the differences. Might be minor tuning differences. I've swapped the AFM T-vis ECUs from my AW11s, AE82s and the AE86s I've had over the years. Can't tell the difference in any tuning. I do have a bastard ECU that has a higher rev limiter, cuts out just north of 8500rpm. As for the rest of it, the distributors, ignitors, TPS, AFM and such have been interchangeable so far. Yes, I'd like to know if one ECU has a more or less aggressive timing curve than another. 'Til I know the difference, they're all the same.

Toyota8 wrote:so what's the difference?

Probably just the shape and positioning of the clips that hold
the ECU in place. Toyota seem to do that with things like igniters
that appear to be identical, having different numbers according
to which model car they are installed on.

Cheers... jondee86

Only difference I found on some ignitors is the length of the pigtail that goes to the distributor. Funny thing on that is the part #s don't change on the wire lengths. Maybe someone in the factory just stands there and cuts random length wires. ???

not sure of the differences... but here is a partial list........

Good list for cross referencing.

Damn you oldeskewltoy and your exhaustive collection of 4AGE trivia
Now I am obliged to look at the possible differences between the various
ECU's that are in your list These differences do not affect the basic
operation of the ECU, but adapt it to local model or market conditions.

Some that I can think of for the TVIS engine are...
- fuel/ignition map changes to suit the octane rating of available fuel
- EGR vs non-EGR equipped.
- O2 sensor vs mixture control equipped.
- automatic vs manual.
- de-tuning to meet emission standards in some markets.
- MAP vs AFM load sensing.

Non-TVIS, GZE and 20V ECU's will have different plugs as well as substantial
differences in mapping and function from TVIS models.

Oh, and the clips that hold the ECU to the chassis might be different as well

Cheers... jondee86

sirdeuce wrote:I do have a bastard ECU that has a higher rev limiter, cuts out just north of 8500rpm.

A bastard ECU? Where did you get it from? Is it pulling up to 8500 rpm? Because on my factory ECU rev limiter up to 7800 rpm I hit the limiter and it's pulling good!

from RUMOR...... the earliest AW11 ECU doesn't have the same rev cut as the "newer" ones... WHAT that rev cut is... might be 8500?????


Jondee... one TVIS set up you missed... low comp (9.4 to 1), and high comp (10.0 to 1). Low comp = 4AGEC, high comp = 4AGE. The "C" = catalytic converter equipped

oldeskewltoy wrote:from RUMOR...... the earliest AW11 ECU doesn't have the same rev cut as the "newer" ones... WHAT that rev cut is... might be 8500?????


Jondee... one TVIS set up you missed... low comp (9.4 to 1), and high comp (10.0 to 1). Low comp = 4AGEC, high comp = 4AGE. The "C" = catalytic converter equipped

Basically tought, all North Americans 4AGE have a catalytic converter.

That bastard ECU's part# is 89661-17020, '85-'87 AW11. I se the list above only has it listed as '85-'86,but I've only had '87s and I have 7 of these same #s sitting on the shelf, from '87s. And as for the possibility of it being a tacho anomaly, I tried other ECUs in the same car with the normal fuel cut. Besides, you can tell the difference between 7800rpm and 8500rpm. As for the pull to fuel cut? With stock cams it drops off a tad, noticeably. With the 264 cams it pulled all the way to fuel cut. Tried 272 cams, but tuning fell short with the stock components, but it still pulled hard to fuel cut. It is a kick shifting out of 2nd gear at 85-87mph!

Toyota8 wrote:

oldeskewltoy wrote:from RUMOR...... the earliest AW11 ECU doesn't have the same rev cut as the "newer" ones... WHAT that rev cut is... might be 8500?????


Jondee... one TVIS set up you missed... low comp (9.4 to 1), and high comp (10.0 to 1). Low comp = 4AGEC, high comp = 4AGE. The "C" = catalytic converter equipped

Basically tought, all North Americans 4AGE have a catalytic converter.

yes........

sirdeuce wrote:That bastard ECU's part# is 89661-17020, '85-'87 AW11. I se the list above only has it listed as '85-'86,but I've only had '87s and I have 7 of these same #s sitting on the shelf, from '87s. And as for the possibility of it being a tacho anomaly, I tried other ECUs in the same car with the normal fuel cut. Besides, you can tell the difference between 7800rpm and 8500rpm. As for the pull to fuel cut? With stock cams it drops off a tad, noticeably. With the 264 cams it pulled all the way to fuel cut. Tried 272 cams, but tuning fell short with the stock components, but it still pulled hard to fuel cut. It is a kick shifting out of 2nd gear at 85-87mph!

Did all your 7 ECUs 89661-17020 have the higher rev limiter? I'm asking because the one I have tried on my Corolla GT-S was revving normally.

Out of the 7 ECUs only 1 revs past 8500rpm. That's why I call it a bastard. It is a kick!

sirdeuce wrote:Out of the 7 ECUs only 1 revs past 8500rpm. That's why I call it a bastard. It is a kick!

I guess it's a kick! I want one too!