JDM LOOM QUESTIONS

[AIROCOBRA]

Hi guys , A few questions from a wiring nob.

I have a 2nd hand JDM LOOM ( PREVIOULY FITTED TO A ADM AE86 ) . I have plugged in all the obvious engine conections and following the Big Port wiring guide I have done the altinator and coil mods ( tested each , all ok ) .
My question is thus, as I can find no mods to this loom that have been do before ( was fit to a ADM bigport by previous owner ) do I still need to do the following mods ---------------------------



1. POWER TO INJECTORS ?
2. ECU POWER ?

This is the big port witing guide instructions ---

-On 14 pin plug, Pin 7 (+B1) and Pin 14 (+B ) can be connected together, and go to ignition (or can come off a relay you used for coil power)
-On 14 pin plug, Pin 6 (Batt) goes to constant battery 12V source (ie wire straight from positive terminal on your battery if you want, fused - 7.5amp should be the max you need). There is a battery power wire found in the passenger side kick panel wiring junction box (big thick white wire). Tap into this instead of running an ugly wire through your engine bay.I have done this bit.

For fail safe starting, you may also need to give power to injectors (Yellow wire found on 10Pin plug, Pin 10 (BF)) by joining a wire into the yellow wire and giving it 12V on iginition (again, use the same relay that you may have used for coil, but might be drawing too much current).



If so then when it instructs for me to connect to black /orange trigger wire for power to do injectors (1) and ecu power up (2) . Does it mean just connect to that wire (black /orange ) , our does it mean repeat the same fused relay mods that I did when I did the coil wiring.

Hope this makes sence .

[AIROCOBRA]

No sparkie out there that can answer this ?

[Nikkojoe]

When I wrote that I meant use the black orange wire as a trigger for a separate relay to make a secondary 12v ignition source. You can use this secondary source to power the injectors and give power to the ecu.

However, if you want to be extremely neat, the engine bay fuse box on an 86 has a spot for efi main relay. You need to get the factory fitting relay and then work out which is the output pin under the fuse box.

Further more if the loom is a zenki jdm loom, the injector power wire is located on the middle firewall plug along with starter, coil power, reverse lights, water temp, and oil pressure.

[AIROCOBRA]

Thank you for that , I was on the right track , now you have confirmed . Thanks Again .

[AIROCOBRA]

Right guys the wiring nob can't get the car to start.... I have done the wire up with some sucess, but for the life of me I can not get power from the coil to the distrubutor.
On the sucess side ----- ECU has memory power ---- Ecu has ign power via relay set up ----- injectors have power via relay ----- ciol has power via relay , fuel pump works when car is turning over. Can hear the injectors click. But off course all that is of no use if I can not get power to the distributor.

On ignition I have power at both + and - posts on the coil. I have inspected all the earths ,checked the fuses , checked the connections they all seem ok. I have swapped both the coil and the ignitor off a running AE82 4AGE 16 V , still no spark . I direct wired batt + to coil + --- still no spark . Attached a timing light to no 1 no light flash.
Although every time I try to start the car I get one spark , a cough at the intake , but as I continue to turn it over it all goes dead in the spark department.

I am not sure what to try next any ideas from people in the know I would be very greatfulL . Rebuilt this car for my son , new paint etc etc and this and rego are all that is stopping this project from living.

[slide86]

you have done everything right, trust me.

I had this problem once too. man......what did i do to fix it.......it was a while ago.

all the things you have done above are 100% correct. it should run, ill have to think.......

[Nikkojoe]

Check your earths! Main earths being:

-Thick engine earth from block to body (and smaller secondary ones)
-Make sure igniter is bolted down and earthed well<<< this could be your issue (i had a poor earth once and it did exactly as you said)
-Make sure loom is earthed on intake manifold

[AIROCOBRA]

Still no start !!!!!!!!!!!!!! Bloody frustrating , Car now has plenty of good earths --- 2 x block to body , head to body , loom to inlet manifold , coil/igniter to body x 2 , body to neg battery , all relays earthed to neg batt. Ecu to body etc etc etc .

Turn it to ignition and I have power at both + and - posts on the coil and every thing else is a go . But soon as I turn to start , the car gives one spark to distributor, a cough at the intake , then nothing, as I continue to turn it over it all goes dead in the spark department.

If anyone has had this problem and fixed it please let me know.

[Nikkojoe]

Check your leads, including coil lead.

[AIROCOBRA]

Leads are new ( no garantee I know ) but I tried them on the AE82 and they worked fine . I am no electrician but even thou the big -- 3 ( ECU , COIL , INjECTORS ) are on seperate relays they all have been taken off the black/orange wire that was connected to the previous set up on the 4a. Could it be that there is a voltage drop on start ----- and I am not getting the full 12v at that moment ??????????????? . Might check that out tomorrow . If so I will have to find a 2nd power out let on ignition ( black/orange ) , but not on this side of the loom I expect . What do you think , plauseable or am I barking up the wrong tree .

[Nikkojoe]

From what I can see, all wiring is good.

Id say its something else which is the issue...

Try changing dizzy assembly with the ae82 one (if you havent already).
Check the loom, make sure important pins have continuity across them and that no wires other than earths earth to body.
Swap the ECU over with the ae82 one.

Check error codes on ecu (wire up a test light to the check engine light pin (the pin on the ecu is an earth when ativated, so connect one end of the test lamp to 12v and the other to the pin). Bridge the check connector TE1 and E1 pins (connector located in a diagnostic box on the kouki, or yellow round plug usually with a cap located dangling above the a/c pipes on firewall). TE1 and E1 wire colours are blue with wite and a brown wire (e1- an earth). If you cant find the diagnostic connector, the locate the pins on the ecu side and bridge them there.

[AIROCOBRA]

Now the starter motor will not engage, tested it , it's fine . Time to give it a break till NEXT WEEK . Got a hill clmb on Sunday so better prep the other AE86 and put it on the trailer . Come back to this problem next week . Thanks for the help so far , not going to let it bet me !!!!!!!!!!

[AIROCOBRA]

Well in the interest of my health I gave up and trailed it to a sparkie ( $125 per hour ) Several hours later the following was found.

---- Starter not working due a pin inside the main connection had broken in half ( probably due to all the clipping , unclipping and tugging during the various investigations.
----- Low voltage at start was caused by a partly severed wire inside the the 2nd hand JDM loom , it was inside the big connection plug . I would never have found it . I just have enough electrical knowledge to be dangerous. But I am pleased to say that the wiring mods I did where all found to be a-ok .

Thanks to the guys that responded to my cry for help .Just got to get her running a bit better , put panels on , new exhaust ----- then the dreaded rego !!!!!!!!!!And another 86 will return to the road.

[maxhag]

good to hear Bob...