ECU for a 1970 Toyota Corona

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DonaldBecker
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ECU for a 1970 Toyota Corona

Post by DonaldBecker » Thu Sep 05, 2019 3:10 am

Well, that title might be slightly misleading. I'm actually interested in an ECU for a Toyota 1JZ-GTE that we stuffed into the Corona. (The Corona is pretty much a micro-car. The result is absurd. This is a Lemons car that we first raced with the original engine and two speed automatic transmission, winning the IOE prize.)

The 1JZ-GTE is a inline six cylinder engine with twin turbos. It was only available in Japan, and this particular engine came from a Soarer.

Unlike the later versions (VVTi and 2JZ) there isn't any complication with the turbo control -- the two turbos are symmetrical rather than sequential.

It has port fuel injection, with six injectors controlled as three pairs. Which is slightly annoying because a pair probably pushes the limit of typical injector drivers.

The 1JZ uses a VR crank sensor with a twelve tooth wheel on the crank, and two VR cam sensors each sensing a single tooth. It appears that the two cam sensors are redundant in this engine, perhaps as a legacy of an earlier generation that had multiple wheels in a distributor to simplify the spark logic. Or perhaps they were already planning on variable valve timing and put sensor on both intake and exhaust cams.

The idle control valve is a stepper motor. Unusually it requires four low side drivers. Apparently the extra coils and wiring was cheaper than a pair of H-bridges in the ECU.

The engine has two resonant knock sensors and a single heated oxygen sensor. It uses a unique 2.2 bar MAP sensor that may have a offset. There are two thermistor temperature sensors, water and intake air.

The throttle position sensor is a single wiper type with an idle contact (contact to ground when the throttle is closed).

Right now my goal is to construct a plug-and-play ECU that allows us to swap back to the factory ECU with no modification. That means supporting two (or three) VR inputs, three injector channels for injector pairs (which implies a current of 2.0 to 2.2 amps), and six logic level ignition outputs to the stock igniter. Secondary goals are to have idle control working (four low-side drivers) and some pretense at knock sensing.

We can easily add a second MAP sensor and a wideband oxygen sensor, which won't impact the original ECU.

My background is in EE and CS, with a broad range of experience. I've done quite a bit of open source software, and designed a number of boards at the hobby level.

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russian
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Re: ECU for a 1970 Toyota Corona

Post by russian » Thu Sep 05, 2019 3:27 am

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russian
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Re: ECU for a 1970 Toyota Corona

Post by russian » Thu Sep 05, 2019 3:36 am

DonaldBecker wrote:
Thu Sep 05, 2019 3:10 am
Right now my goal is to construct a plug-and-play ECU that allows us to swap back to the factory ECU with no modification. That means supporting two (or three) VR inputs, three injector channels for injector pairs (which implies a current of 2.0 to 2.2 amps), and six logic level ignition outputs to the stock igniter. Secondary goals are to have idle control working (four low-side drivers) and some pretense at knock sensing.
Sounds pretty close to Frankenso? It has stepper on the schematics, it has hip9011 which potentially kind of should work theoretically, it has two VR channels out of the box.
DonaldBecker wrote:
Thu Sep 05, 2019 3:10 am
I've done quite a bit of open source software
Right. A bit. I see :)
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

DonaldBecker
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Re: ECU for a 1970 Toyota Corona

Post by DonaldBecker » Thu Sep 05, 2019 3:54 am

Yes, that's the car.

It's now about 1.5 feet wider, with the engine halfway through the original firewall, the exhaust directly through the rear passenger door, driver's seat where the rear seat was, and the radiator in the trunk. And changed from leaf springs to coil-overs suspension, using the subframes from the Supra and lots of fabrication for the strut towers.

It was out of action for a few years after it was almost crushed by a redwood tree that went through the garage. I was supposed to be there working on it that morning, but was late. The two guys that were there were lucky to have moved to the rear. The rollcage was the only think that held up the collapsed garage roof.

One complication is that the car has moved. Rather than being five minutes away, it's now 200 miles away. So my priority is having multiple options ready to try, lowing the risk that things can't be made to work with the hardware at hand, and spending disproportionate effort on diagnostics. And since it's Lemons endurance racing, making certain that it's very reliable or easily swapped.

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Re: ECU for a 1970 Toyota Corona

Post by kb1gtt » Thu Sep 05, 2019 10:09 pm

Do you know your connector? We have a pile of connector adapter PCB's. Perhaps a frankenso with adapter cable would be a good start.

Are you looking for the same mounting? Frankenso uses the OEM enclosure which makes for easy swapping.

We also have a switch over board. Basically wire both at the same time and move fuses to pick which ECU is used. It was used once upon a time were @russian ran an engine on the OEM ECU. He moved one injector, then one spark. Once one cyl was tuned to match the OEM he then moved over there other cyls. Eventually all cyls migrated to his ECU.
Welcome to the friendlier side of internet crazy :)

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Re: ECU for a 1970 Toyota Corona

Post by DonaldBecker » Fri Sep 06, 2019 12:30 am

From my notes, in the hope that it would be will be useful to others in future searches:

The ECM uses a connector block made by Tyco (e.g. TE, TE Connectivity, AMP). There are four pockets/ports with 34-22-16-28 pins. This is distinguished from other Toyota ECU connectors by having four rows of pins. The TE Connectivity part number is 1-5178203-6 or 1-178203-6.

Drawing
https://www.te.com/commerce/DocumentDel ... er+Drawing
https://www.mouser.com/datasheet/2/418/ ... 133399.pdf


Other ECMs with the same connector block are
89661-07010 1995 Avalon 1MZ-FE A/T Note: wide case
89661-07050 1996 Avalon 1MZ-FE A/T
89661-07081 1997 Avalon 1MZ-FE A/T Note 98+ 07220 is different, single layer small case
89661-08010 1998 Sienna 1MZ-FE A/T Note: 1999 08020 is different
89661-08011 1998 Sienna 1MZ-FE A/T Note: 1999 08020 is different, single layer small case
89661-0W010 1996 ES300 1MZ-FE A/T Also 97 T100?
89661-34170 1995 T100 5VZ 2x4 Note: narrow case, used ECUs expensive
89661-3D380 1998 4Runner 3RZ-FE 4x2
89661-04040 1995 Tacoma 5VZ 4x2 A/T
89661-04700 2000 Tacoma 5VZ 4x4 A/T Note: single layer small case
1996 RX7 JDM only Note: very different pinout

Later Supra ECMs use a three block 120 pin connector. This is the target connector of the AEM controller. TE 1-178405-6 120 Pin Supra 2JZ ECU
https://www.te.com/usa-en/product-1-178405-6.html

ECU Masters uses an adapter to standard Delphi 24 (or 39) pin connectors
HCCPHPE24BKA90F (Black, keying A), HCCPHPE24GYB90F (Grey, keying B)
https://www.mouser.com/ProductDetail/Ap ... zo4Q%3D%3D

This connector is still available for about $50. Removing one from old ECUs is difficult but feasible. It's assembled with a few pins bent to hold it in place during soldering, so it won't just drop out. I found that desoldering needles worked best.

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Re: ECU for a 1970 Toyota Corona

Post by russian » Fri Sep 06, 2019 12:52 am

DonaldBecker wrote:
Fri Sep 06, 2019 12:30 am
The ECM uses a connector block made by Tyco (e.g. TE, TE Connectivity, AMP).
100 pin part number added to https://rusefi.com/wiki/index.php?title ... rs#100_pin
120 pin was already there :)
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