Not sure how much it will help but you could remove the pins from 3Y and 3W and switch them to see if you get the same results at pin 3Y.

 

Ok I'll try that

 

Update: Just swapped the rotor 1 and 2 primary pins at the ecu harness and the dead signal moved to rotor 1 and now have signal at rotor 2.

 

I also disconnected both TPS and Boost sensor with no change, Also both pins 3Y and 3W both have 9volts at the pins with the key to the on position

 

You left the plugs at the injectors alone but you switched just the pins. Correct? If so, then the problem appears to be w/the wiring/plug and not the ECU or injector.

 

Forget what I said in the previous post for I did not read what was typed and it was obviously wrong on my part. The injector and wiring are both shown to be good for the rear primary rotor. The problem is related to the ECU for some reason. Either it's being asked to cut the signal to the rear rotor , or perhaps it is a grounding issue. I don't think the CAS is the cause. At this point perhaps you should address the grounding side of things.

 

One thing you need to verify. Are pins 3W and 3Y on the top row of the ECU plug and side by side. They should be on the top row and the most far left two positions.

Another thing is you mentioned you pulled the ECU and placed it in another car and you spinned the CAS and both primary injectors clicked. The question is which CAS did you use? Did you remove the CAS in the other car you placed your ECU in and spin that car's CAS or did you use another CAS?

 

i might try another ecu, and or find the pin that does the speed limiter cut. i'll have a look in the diagram and see if i can find it

 

piece of cake, its labeled in english, pin M in JDM, or 1M in 'murica, is the speed cut.

the US function is a mileage switch, so its possible that the switch switched, and the ecu turned fuel cut on.

 

And how many miles does your cluster read?

 

Awesome I'll check this tonight. Is that circuit a power or ground?

 

I'll check mileage when I get home tonight

 

Your cluster is sending a signal to the ECU to tell the ECU how many miles the car has. Below 20k and the ECU receives a 12 volt signal on the wire to pin 1M. From over 20k to 100 k the ECU then receives a ground signal. This repeats over again after the car goes over 100k. If the cluster recently changed from below 100k to 120k or from just under 120k to just over then the signal at the ECU changes. This change could cause the pin 1M to change its voltage and thus could be causing the fuel cut at the rear rotor primary. This is what j9fd3s is pointing to and why I asked how much mileage the cluster had. And the ECU on a USDM car receives this info to change how the emissions work as it depends on the age of the car/engine.

 

correct, the JDM ecu uses the same pin to cut fuel to the rear rotor when you go faster than 118kph, i think since the JDM people remove a screw, that when the ECU sees voltage it cuts the rear rotor.

it would also explain why the car ran fine, and then didn't

of course we could be wrong too, but easy to check

 

I tested pin 1M according to the diagram in foxed its 7th pin from the right (top row) wire color is blue with a black stripe. With the key to the on position I got a ground source there, I tried spinning the CAS and signal didn't change

 

120,011 miles exactly on the odometer.

 

Btw: the cluster on the car still appears to be the factory USDM as it reads in mph and there's no factory boost gauge if this matters.

 

Reading the info I decided to remove the pin and retest and now I have signal at both primary rotors! I'm going to put the car back together and see what results we have!

 

The signal for that pin comes from the gauge cluster and is based on the mileage as registered by the cluster, the CAS has no bearing on this wire in any manner.

Secondly, if you have no boost gauge then the cluster is not from a turbo car (can't remember asking if this car was always a turbo or a turbo swap).

Since you just eclipsed the 120k mark then the signal on that wire went from having 12 volts to one of a ground. Makes some sense that you would try to return that pin back to a 12 volt signal and see if that affects things for the better. How you would do this is up to debate but try removing the wire/pin from 1M. Then shove something into the back of the plug where the pin resided in which you could place 12 volts to it (an unbent paper clip will work). Pin 1B (Black/White wire) has 12 volts w/key to start and on. This would be a good wire to mooch off of. Since you really don't need this pin you could also just cut the wire about three inches or so away from the plug and use the remaining part of the wire to tie into the 12 volt supply. You might do this after you initially test the pin w/12 volts to see if it helps and if so then to cut the wire as suggested.

Also, you could depin 1M, place the plug back into the ECU, place a paper clip into the place vacated by the wire/pin and w/key to on see if you get 12 volts. If you do then just leave the pin pulled from the plug and leave it at that.

 

Good info, ill try this and report back. Thanks

 

I just fired up the car and both rotors are working properly, I haven't really tried driving the car as I still will use a 12volt source in the missing pin in case it affects anything else.

I can't thank you guys enough for all the help. I definitely did not see this repair going this direction.

 

If you read 12 volts from the depinned slot then that should be good enough. Anyway, it sounds like winner, winner chicken dinner and j9 deserves the greatest amount of praise in this. I'm not very familiar at all w/JDM components, but I learned something today which hopefully will allow others to remedy a similar situation in the future. Thanks j9.

 

i was lucky enough to come across the JDM service books