MAPed Blue Top Swap, NOT staying running! Please Help?!

[Nanaki]

Okay.. This is completly melted my brain trying to figure this out.. I have a AE86 GTS and the Motor was toast so I pulled the USDM motor/Tranny/Engine harness/ECU, and all.. Now I got a Japanese blue top MAP sensored motor & T50 Tranny /harness/ecu/ Gauge cluster the whole nine yards. Now.. After replacing the Dizzy and having to buy a igniter, We got it to start up and Idle but after idleing for about 20 - 30 secs it dies. instantly dies if you press the gas pedal... My thoughts is its not getting the right voltage to the 4 main injectors and its only running off the cold start injector till the primer fuel runs out?.. Is there some type of wiring I need to do? Im so confused..... Can anyone help me out please???

Also take note that I have noticed there is a black sqaure like plug that sits on the fire wall in the engine bay. One half of the plug is connected to the engine harness the other half looks like it goes into the fire wall and splits into the drivers side finder ( LHD )

Now.. on that plug on the Japanese engine harness side there is a Yellow ( Main injector power wire?? ) in the center the USDM side of the plug has nothing there.. I did jump the yellow wire to the black with orange on the engine harness side and it seems to get it to idle as stated before. Other wise it wont really idle at all.. Not sure if this is how that is supposed to be hooked up. I also tapped in the Black with Red wire that looked to have been cut on the engine harness ( Around where the igniter plug is ) it has one wire and a small black plug. I tapped that into the black with orange so that it gets power when the key is put into the On position.. If any other info is needed let me know. Im just so confussed as to why its not working........ Im soooooo Confused!!

[Ivan141]

Pictures of the connectors in question might help..cause it's a bit difficult to follow.

[jondee86]

Cold start injector only runs while cranking, so engine will fire and then
die quickly... after 2-3 seconds. Faster if you open the throttle

If the big square plug is disconnected, you can jumper 12 volts directly
from the battery to the injector common power supply. Sounds like you
already did that if the engine will idle for 30 seconds.

Now you need to check if you have low impedence or high impedence
injectors. From memory, I think high impedence are 12 Ohms and low
are like 2 or 3 Ohms. Low impedence injectors need an injector ballast
resistor installed to restrict injector current draw. Its a diecast metal box
about the size of an igniter, but with small cooling fins on the cover, and
less wires.

If you need one, but don't have it, the car will run poorly, or not at all

Cheers... jondee86

[Nanaki]

some photo's

do I ohm the injector plug? or the injector its self? or how do I do it? With power and key to on position?

If I do need it does anyone have a part number, or know it?

[jondee86]

Just pull the plug off the injector and measure the resistance between
the two pins on the injector.

Cheers... jondee86

[Nanaki]

Now.. from what I can tell I have the 2 ohm injectors. I have the Injector Resistor from the USDM car.. and after looking at the Resistor and the plug on the USDM engine harness I think that if I tap the blue and red wires together and then connect them both to the yellow on the Japanese harness.. Then the black with orange ( Might have been black with yellow. ) to the black with orange to get 12v with the key at the on position. It should in turn work or am I wrong?

Also Im going from what I jondee86 said in another of my posts of what the Injector Resistor looks like.

[Nanaki]

Well at trying that it only seems to fire up for 3 - 5 secs.. I think I was over stating when I said 30 secs I think the max ever was maybe 10.. anyways. Maybe its now cause the timing might be off?

****Update**** I Moved the vac line for the MAP sensor to the throttle body where I had it looped before. And now as for the Injector resistor, I have the Blue and the Red tied together and tapped into the yellow. and then Black with Orange stripe to Black with orange stripe.

It will now start and idle up for a while maybe about a good minute or so and if left to idle it will die. OR any time you give tap the throttle or step on it at all it will kill over as well.. Is this a Timing issue or maybe fuel pump?... Or just not enough fuel pressure for some reason?

[koh]

i would check the fuel supply,sounds like it could be a waek pump or restricted pipe

[Ivan141]

And make sure you got the sensors in the head connected properly, that has also been known to cause these kinds of problems.

[jondee86]

The solenoid resistor (injector ballast resistor) has one wire going in and
two wires coming out. Resistance between the wire going in and either
of the wires coming out should be 2-3 Ohms.

The wire going in should be connected to a 12V power supply that is ON
when the ignition key is ON. Each of the wires coming out should be
connected to supply 12V power to one pair of injectors.

The injectors are arranged in parallel connected pairs. So each wire out
of the ballast resistor powers two injectors, with the downstream side of
the injectors being joined together, and then connected to the ECU. One
wire (two injectors) to ECU pin 10 and one wire to ECU pin 20.

It does not sound like you have this wiring correct. Check it, change it
if necessary, then see how the engine runs.

Cheers... jondee86