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4agze swap wiring woes!

Posted: Thu May 09, 2019 8:08 am
by nagz
Alright y'all,

background story is I bought a 76 corolla sr5 with a non-running 4agze swap. The previous owner has had it for a number of years and wasn't able to ever get it running but I think all the bits and pieces are there but just needs a wiring fix. He suggests to go to a standalone like a megasquirt or haltech. I would personally like to try and get the 4agze running off all the parts that are in the car and see how it goes. Wiring is a bit of a mess though and I suspect my problem could be somewhere in the harness. I am new to the corolla world, not bad at wiring I can sort most things out and know how to run a multi meter but some help with the logic behind whats going on in the harness would sure help.

The motor is out of a 4agze afm/dli ae92. I am using the aw11 mr2 ecu pinout and wiring diagram off this website and it all seems to match up with what i have in the car but the distributor/cas is obviously slightly different.

The car straight up does not start. Turns over and once or twice i've gotten a little pop and sputter but she will not go. I even tried running it off starting fluid and nothing. I've verified that I have spark on all 4 cylinders. i've verified cam gear and crank timing and reinstalled the cas with the dimples lined up.

I began looking at the wiring that goes into the ecu and verifying grounds. my sensor grounds are a little suspect. we had the e22 wire(sensor ground 2) hooked to one of the main power grounds with a splice connector. I clipped it off and just tried pumping to the e2 ground to see if that would make a difference and nothing still.

Not anywhere near my breaking point yet but looking for some advice. I want to double check continuity from e2 and e22 in the harness to the THW THG THA AFM and TPS. I think these all carry sensor ground, guessing they wouldn't have ground to complete a circuit with a volt meter from battery positive to e2 and e22 but should have continuity thru the harness?

Also i am going to reattach the brown ground on the intake manifold tonight, i am talking the one by the injectors not the one from the back of intake to firewall, its currently hooked to the cold start injector which is all ripped off and rtv gasket'd, I am guessing power wont travel through rtv. where does this wire usually hook to on the intake?

any other advice y'all can give me? I am suspect there will be a few wiring fixes here i'll be doing, 3 maybe 4 splice connectors by the ecu I don't like the looks of.

Re: 4agze swap wiring woes!

Posted: Thu May 09, 2019 2:31 pm
by jondee86
1. The ECU grounds are the three (+/-) brown wires attached to a single brass ring
connector. These must be bolted down and the usual place is on top of the intake
manifold towards the rear of the engine.

2. ECU sensors are supplied with 5V by the ECU and the sensor ground wires must be
connected to the appropriate ground pin on the ECU. They cannot be connected to a
chassis ground.

3. Not sure exactly what components you are using but you cannot mix late model GZE
(CAS and coil packs) with early (dissy and coil) parts. The ECU and ignition components
must all come from the same OEM setup.

Cheers... jondee86

Re: 4agze swap wiring woes!

Posted: Thu May 09, 2019 7:26 pm
by nagz
jd86 thanks for the reply bro!

1. The ECU grounds are the three (+/-) brown wires attached to a single brass ring
connector. These must be bolted down and the usual place is on top of the intake
manifold towards the rear of the engine.


I moved it, put it on the intake manifold at the front bolt where the harness protector bolts down, the plastic was already broke on the protector and it reached.

2. ECU sensors are supplied with 5V by the ECU and the sensor ground wires must be
connected to the appropriate ground pin on the ECU. They cannot be connected to a
chassis ground.


if their are 3 brown wires that connect to the intake manifold(on one ring termial) does mean E1, E2, and E22 are ecu grounds? and E01 E02 are chassis grounds? it seems like E1 is a chassis ground on my car.

3. Not sure exactly what components you are using but you cannot mix late model GZE
(CAS and coil packs) with early (dissy and coil) parts. The ECU and ignition components
must all come from the same OEM setup.


pretty sure i have all the correct components but maybe you can verify?

ecu: 89661-12170
afm: 22250-16070
cas: 19300-16010
igniter: 89621-12030
coilpack: 90919-02179
tps: 89452-20050
resistor pack: cant see anything

are there any other components that could be causing a problem?

i've been trying to find a pinout for the AFM but not having any luck. the harness has been extended and i am not so sure its wired correctly. If the 4agze aw11 diagram is also correct for my motor the AFM pinout should it be:

(left)
pin 1: 12v power (green-red wire)
pin 2: chassis ground to COR,E1,E01,E02 (white-black wire)
pin 3: THA air temp (black wire)
pin 4: VC goes to TPS as well (yellow wire)
pin 5: VE (yellow-blue)
pin 6: B22 ecu ground common to tps, thw, thg (brown wire)
(right)

but how is it supposed to be pined out in the connector?

mine isn't wired like that, its similar but not exact. its actually a 7 pin connector with one empty slot and if its layed out in a left to right pinout 1,2,3,4,5,6,7 looking at the AFM with the air filter to the left and with the connector having 2 locating bumps facing up and 3 bumps facing down (the bumps that align the connector so you cant put it upside down.

(left)
pin 1: 12v power (green-red wire)
pin 2: chassis ground to COR,E1,E01,E02 (white-black wire)
pin 3: empty
pin 4: yellow wire
pin 5: blown wire
pin 6: yellow-blue wire
pin 7: black wire
(right)

is it possible this connector fits the AFM but the pinout of the wire colors are in the incorrect pinout for the AFM meter? my plan is to check continuity of the wires in the harness and get the pinouts wired how the FSM says 1,2,3,4,5,6 should be and see if it works. the hangup is possibly the empty slot on the AFM connector but if i ignore its there and proceed wiring it up like 1,2,empty,3,4,5,6 do you think i will have success?

Re: 4agze swap wiring woes!

Posted: Fri May 10, 2019 1:12 pm
by UNLIMITED 86
Do you have fuel pressure? Is the fuel pump still controlled by the COR? You should be able to hear the fuel pump turn on but it's better to verify this with rail pressure (pump could be running but not producing adequate pressure to get fuel atomization).

When the AFM detects intake flow, it provides a ground signal to the COR, which turns your fuel pump on. Check the wiring to make sure nothing got mixed up when the wires were extended.

Im not sure what harness youre using but in an AE86 the main ground for the AFM is connected on the left side of the block (small white connector with a single wire that plugs into ground on frame rail). If this connection is missing or going bad, it will prevent the AFM from sending a proper ground signal.

Hope this helps.

Re: 4agze swap wiring woes!

Posted: Fri May 10, 2019 4:13 pm
by jondee86
As far as I can figure the parts you have should work...
89661-12170 ECU, AE92, 4AGZE
22250-16070 AFM, AE92, 4AGZE
19300-16010 CAS, AE92, 4AGZE
89621-12030 Igniter, AE92, 4AGZE
90919-02179 Coilpack, AE101, 4AGZE
89452-20050 TPS, AE92, 4AGZE

For unknown reasons there is virtually no technical information on the web
regarding the AE92 with DLI and AFM. But from what you wrote it seems that
you might find what you need from the marked up diagrams here...
http://opc.mr2oc.com/online_parts_catal ... wiring.pdf

Cheers... jondee86

Re: 4agze swap wiring woes!

Posted: Fri May 10, 2019 6:27 pm
by nagz
UNLIMITED 86 wrote:Do you have fuel pressure? Is the fuel pump still controlled by the COR? You should be able to hear the fuel pump turn on but it's better to verify this with rail pressure (pump could be running but not producing adequate pressure to get fuel atomization).

When the AFM detects intake flow, it provides a ground signal to the COR, which turns your fuel pump on. Check the wiring to make sure nothing got mixed up when the wires were extended.

Im not sure what harness youre using but in an AE86 the main ground for the AFM is connected on the left side of the block (small white connector with a single wire that plugs into ground on frame rail). If this connection is missing or going bad, it will prevent the AFM from sending a proper ground signal.

Hope this helps.


where does the white wire come from? does it come out of the 7 pin connector then to the frame rail or is it attached somewhere else on the AFM? my car pin 2 of the AFM is white-black stripe and i can't see where it terminates but i was assuming to the COR relay. I should recheck that circuit. My fuel pump turns on when i crank and if i jump it i can set fuel pressure or i've been jumping it to try and start the car but that doesn't seem to make any difference. also i can get the fuel pump to turn on if i move the flapper of the AFM so i was assuming the circuit was working correctly but i will try to verify its wired correctly.

on the subject of fuel supply:

The car has never run for me and the previous owner told me it had not ran in a long time so I took the initiative to change the gasoline out and replace it with fresh premium before I even tried starting the car. That stuff was nasty! and i am hoping i got 99% of it out. it looks and smells a lot better now.

with that said It has a pretty major fuel setup going on and I am not 100% sure its hooked up right either.

to break it down for you it has something like a low flow carter inline fuel pump that feeds the top of a surge tank. the very bottom of the surge tank is hooked to another bigger inline fuel pump and that feeds the front of the engine side of the fuel rail. comes from the back of the fuel rail into a fuel pressure regulator with gauge and from the bottom of the fuel pressure regulator back to the side of the surge tank and then from the side of the surge tank back to the main fuel tank. It seems like its hooked up correctly but i am not sure if the return from the engine or return to the fuel tank should be on top or bottom of the 2 side ports? or if that even matters?

the other things i've noticed:

- the fuel system sounds loud as f*ck to me? more like i can hear it in the fuel rail than fuel pump noise though. maybe its aerated?? i am not sure how i'd check that or if there is a way to bleed a surge tank setup so that I have a steady column of fuel at the injector ready to inject.

- there is a hiss sound coming out of the air filter after i stop cranking. its air coming back out of the engine or supercharger or something. The motor sucks down hard so it must be strong? i need to fix the intercooler couplers too as one maybe two suck in all the way and block off flow after about 10 secs on cranking. Seems weird to me though as I'd think it should just free flow, unless something is blocked in there supercharger or air stream or something? maybe my air flow meter never opens up when i crank the engine. I've tried unhooking some intercooler pipes but doesn't matter still no start.

I don't know really this is just some project I picked up and I am trying to diagnose someone else work so it literally could be anything. I am hoping I can get it figured out though, i really like the car and if it pans out it will be worth putting the effort into. trying to cross anything logical off the list but i can only get so far on it in the spare time I have. i am sure you guys know how it is wrenching on car!

jondee86 wrote:As far as I can figure the parts you have should work...
89661-12170 ECU, AE92, 4AGZE
22250-16070 AFM, AE92, 4AGZE
19300-16010 CAS, AE92, 4AGZE
89621-12030 Igniter, AE92, 4AGZE
90919-02179 Coilpack, AE101, 4AGZE
89452-20050 TPS, AE92, 4AGZE

For unknown reasons there is virtually no technical information on the web
regarding the AE92 with DLI and AFM. But from what you wrote it seems that
you might find what you need from the marked up diagrams here...
http://opc.mr2oc.com/online_parts_catal ... wiring.pdf

Cheers... jondee86


appreciate your advice! that must be the correct pinout as it matches the wire colors on the AFM plug. I've got it wired up like that now. still no start.

i am waiting for some spark plugs off amazon. maybe that will make a difference. it will be reassurance anyways that they are good once i have them installed and gap'd properly.

Re: 4agze swap wiring woes!

Posted: Fri May 10, 2019 8:42 pm
by jondee86
Just a few random comments...
- on the GZE as I understand it, the clutch is disengaged when out of boost. So
during cranking the s/c should not be turning.
- there is a bypass valve with a vacuum servo that opens at light load to allow
air to bypass the s/c. This should be open when cranking.
- it is not unheard of for injectors to get gummed up if they have sat for a long
time with fuel inside. After you have been cranking for a while you can pull the
plugs and make sure that they are all wet with fuel.
- if you are getting fuel to all cylinders but no combustion, prolonged cranking
will foul the plugs and they will not fire. If so, time to fit a clean dry set.
- if the plugs are not fouled, a squirt of starting fluid should at least get a brief
burst of firing.
- with DLI ignition the engine is fired in wasted spark mode. The ECU sends a
signal to the igniter telling it which coilpack to fire. You need to check that the
coils are firing the correct two cylinders. I wrote a bit about this on another
forum a while back, maybe it will help. Here is a link to the post...
http://www.aeu86.org/forum/Thread-4agze-wiring-problem

Cheers... jondee86

Re: 4agze swap wiring woes!

Posted: Thu May 30, 2019 8:14 pm
by nagz
making progress over here!!

so I rewired the AFM, installed new spark plugs, filled new fuel in the tank, sent injectors out to get cleaned and tested. I had been missing a ground wire on the ECU for sensor ground E22, it wasn't hooked to anything when I got the car and I was wondering where it had to go so I dug into the harness. I was able to chase back from the cylinder head to firewall and find the matching wire color, found where it was crimped to another ground wire and the insulating sleeve that would ground your shielded pairs. found where it went and it was wired to a chassis ground. I ended up cutting it off and attaching it back to the pin on the ECU. Got everything back together and she fires up pretty sweet now. had to feather the throttle open to get it to run but its almost drive-able the way it sits now. not 100% what all was the issue but got my basses covered. now I just need to get a intercooler figured out and replace a missing exhaust stud but should be able to drive it next week if everything works out. Pretty stoked! will keep you guys up to date once i make some more progess. Thanks for all the help so far!