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MaximusPsychosis

7AFE and electrics into a AE82

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Hello children.

So I went out on a little impulse buying and got myself a 7AFE, it has most of the engine bay electrics, but not the ECU/cluster side, I am assuming that I need the cluster, ECU and wiring to get things going. Since its going into a AE82, and that lacks any of this electronics, I believe I have to rewire the cluster with a AE101/112 cluster, so my question is, anyone got a wiring diagram and wire colour codes for a AE101/112?

I also assume the speedo is electric controlled (ECU'ed and all that), not cable controlled too? so I cannot just slap on the ol'C52 to the backside of the engine, and run the ol' cable.

Anywhozle
see how things go

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You should be able to put that engine and use your standard cluster. Very simple engine when it comes to wiring (compared to modern engines anyway)

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Use the cable driven speedo, and keep your old cluster and gearbox if you want.  Id assume it would make things a lot simpler.  There's usually only 1 plug that connects the oil pressure light, temp sensor for the dash gauge, starter trigger from the key, reverse lights etc that connects to the non efi related stuff.  Thats mainly what you need to connect to make the cluster light up, just transfer the temp sensor and oil pressure sender from your old engine across to the new as the old engine will run at the same temp as the new and the oil pressure requirements will be about the same, that way you know its all compatible on the new motor with the old cluster.  Less wiring is a better amount of wiring to do.

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Thank you friends!

I'd love to just shove carby onto it to just not worry about the ecu, but it has the electrics, so ecu required. (unless I can shove an old 4AFC plenum right on the head)

So going by what you said, the ECU doesn't need that info from the engine that the cluster uses? AKA the oil temp/pressure water temp, rpm, speed, etc?
on that note, does the ECU push the same analogue data the old cluster uses? so basically instead of wires from the sensor to cluster, sensors go to the ecu then the old cluster.

none the less, the wiring diagram should help a lot! thank you Hiro!

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14 hours ago, MaximusPsychosis said:

Thank you friends!

I'd love to just shove carby onto it to just not worry about the ecu, but it has the electrics, so ecu required. (unless I can shove an old 4AFC plenum right on the head)

So going by what you said, the ECU doesn't need that info from the engine that the cluster uses? AKA the oil temp/pressure water temp, rpm, speed, etc?
on that note, does the ECU push the same analogue data the old cluster uses? so basically instead of wires from the sensor to cluster, sensors go to the ecu then the old cluster.

none the less, the wiring diagram should help a lot! thank you Hiro!

In the AE102 the speed sensor connects to the dash, and then there is a signal from the dash to the ECU (where the circuit shows a transistor and a pull-down resistor).  I believe if you're running the 7A ECU without that feed from the cluster then the ECU will throw a code 42 and you may get some performance issues.

 

Have you looked at running an AE82 Twincam cluster?  Might pay to check the wiring on them and see if they have the speed sensor output (since they were EFI as well but with a cable speedo).  Get a speed sensor and speedo cable from a Twincam to suit the dash (might be cheaper than getting a whole 4AGE gearbox to suit, I'm assuming you've either got a C50 or an auto at the moment)

Edited by Hiro Protagonist

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I have never found a twinky dash (looked years ago), well one that wont clear out my bank. going by the yella book, the wire/pin for the speedo on the twinky cluster is #20, yet for the bog standard cluster its the door light.. :/ sooo yeah, getting even that to go in look like it requires the ecu'ed wiring, since every pin is different.

I have the C50/52 strapped to the old 4A-C that the 7A is taking over. don't want no A141E.. if i can de'E it, maybe shove it next to the old AE80 and its 2A lol (needs a 4th gear)..

So, need speedo outta twinky, and pin 20 to SPD on ECU.. tacho looks to be free off the ecu, only the black wire feeds back to it. Red/Yellow wire to engine check light, water temp spliced off white wire going to THW?

the rest should be already there.

anyway, plenty time to get it done, I'll definitely get some pics and a write up with this, maybe someone later will find a use for it.. if I don't get lazy over it..

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My information regarding the cluster was only regarding the cluster.

 

The ecu will have temperature sensors for air and water, control the ignition, and fuel levels, its a complete separate system to what would traditionally make the dash work, with the one model specific exception above about the speed sensor.

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well yeah it looks to be the best way to go, I thought I might look into the wiring for it anyway.

The old cluster has the 2 screw points for the speed sensor, but they are coated over (the green coating) and the sensor is missing. I had the thought of getting a AE92 cluster and popping out the sensor to see if it fits. If not, I may have to hunt down a cluster from a twinkie..

unless I could just mount the guts of a AE102 cluster inside the old cluster..

I might call a few local'ish wreckers to see if they have a twinkie cluster.

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I gotta ask, why is there only 2 injector fire wires off the ECU? does 2 injectors fire at the same time? isn't that just a waste of fuel?

Edited by MaximusPsychosis
spelling of words

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23 minutes ago, MaximusPsychosis said:

I gotta as, why is there only 2 injector fire wires off the ECU? does 2 injectors fire at the same time? isn't that just a waste of fuel?

Batch-firing injectors is quite common as it simplifies the control and wiring.  With sequential injection (ie every injector separately wired) you need both a cam angle and crank angle sensor to determine when the cylinder is at the start of the intake stroke (as the crank rotates twice for each rotation of the cam, just knowing TDC on the crank isn't sufficient to determine which stroke you are on).  Sequential is more efficient and you have less fuel floating around in the inlet manifold waiting for a valve to open, but it is more complicated to control.  It also has the benefit of lowering the duty cycle on the injectors by half (which is a good thing)

Wasted-spark (where spark plugs are fired in pairs) is also common, for the same reason (even though it means the spark plug going off at the top of the exhaust stroke) and means you can have a single coil being shared between two cylinders.  Because the 7A uses a distributor and a single coil it doesn't run wasted-spark though (the distributor is run directly from the cam so each HT lead gets power one at a time)

Edited by Hiro Protagonist

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so the 7A dizzy doesn't use hall effect sensor? sorry, I'm used to the falcons sequential system, it uses a 7 tooth (+one missing IIRC) halls in the dizzy to determine where TDC is on the motor to start the injection cycle...

ah well, cannot complain, not going all out with this thing as of yet.. the wast injection isn't really wasted, its just going to sit on the intake valve until it opens anyway and gets a 2nd shot of fuel, only problem I could see off this is the fuel forms into droplets and doesn't 100% burn or become wash off on the cylinder walls

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4 hours ago, MaximusPsychosis said:

so the 7A dizzy doesn't use hall effect sensor? sorry, I'm used to the falcons sequential system, it uses a 7 tooth (+one missing IIRC) halls in the dizzy to determine where TDC is on the motor to start the injection cycle...
 

Sorry got confused - yes the 7A does run a hall-effect cam-sensor in the distributor, but no crank angle sensor (at least not in Australian AE102s).  Not sure on the resolution (ie number of teeth) though.

 

Ignore what I said earlier about needing both a cam- and crank-angle sensor to run sequential injection too (since the 7A doesn't run variable cam timing), my brain has been fried from work lately.

Edited by Hiro Protagonist

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1 hour ago, Hiro Protagonist said:

Ignore what I said earlier about needing both a cam- and crank-angle sensor to run sequential injection too (since the 7A doesn't run variable cam timing), my brain has been fried from work lately.

yeah don't worry about it, I wasn't jumping up and down saying you're wrong, there are some systems that require it, for that extra resolution for working out where the motor is in timing, the crank sensor is needed, especially when you are using multi-coil system on top.
 

2 hours ago, Hiro Protagonist said:

Sorry got confused - yes the 7A does run a hall-effect cam-sensor in the distributor, but no crank angle sensor (at least not in Australian AE102s).  Not sure on the resolution (ie number of teeth) though.

which makes me wonder why they are not using that to run sequential, but like you said, its cheaper to just pulse the 2 wires one after the other in time with the dizzy..

which begs the question, if I was to get the injectors in the plenum instead of the intake runners, so the wasted fuel is also fed to the mix and the piston draws it in for intake, will the system have a fit due to the system seeing it go to rich? or will it be like I said before, its just wetting the runner on compression/fire stroke..

On that note, I was looking into what toyota ECU did do the sequential injection, it seems to be the ones with the turbo/chargers that had them. Then I came across the cute 4K-E ECU, so basic, didn't have 200+ sensors to contend with..

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3 hours ago, MaximusPsychosis said:

which begs the question, if I was to get the injectors in the plenum instead of the intake runners, so the wasted fuel is also fed to the mix and the piston draws it in for intake, will the system have a fit due to the system seeing it go to rich? or will it be like I said before, its just wetting the runner on compression/fire stroke..
.

The odd-timed injection in a batch-fire scenario isn't wasted and just pools behind the valve waiting for it to open, but when you think about it the valve is opening and closing ~8 times a second at 4000rpm there's not exactly a lot of time between injector pulses regardless.  If you're chasing that last kilowatt or two it might be beneficial to go to a full sequential setup, but for more cases it just isn't worth the hassle and added complexity.

Putting the injectors in the plenum is only one step removed from ye-old-skool throttle-body injection (which itself was essentially an electronic carby), a steaming pile of crap.

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