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Electronic Oddity, any in depth ideas?


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Quick update. There is cranking volts getting to pin 81 on the ECM during cranking but with the key simply on there is a voltage drop at Penn 81. I am not getting spark at the moment which is one of the new tests that I redid so I'm going to replace ignition coil once again and see what happens and keep you informed

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I took a picture of the four wire ignition switch and it's too big to upload to this damn site so I'm frustrated I have 4 wires the power feed wire and 3 others.

 

The power feed wire is black with a white stripe. Key on power is the bottom wire and the top wire the top wires black with a blue stripe and while cranking all of them light up except the black one with the blue stripe which stops lighting up when I start cranking is that the one that needs power?

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I have a video to attach for the damn files too big it shows starting to crank in the Noid light flashing after the key is released and also put a new ignition coil on it nothing the ignition switch is working properly and so is the crank sensor in the cam sensor and there is fuel pressure

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Quick update. There is cranking volts getting to pin 81 on the ECM during cranking but with the key simply on there is a voltage drop at Penn 81. I am not getting spark at the moment which is one of the new tests that I redid so I'm going to replace ignition coil once again and see what happens and keep you informed

What input is pin 81?

 

If you have voltage at the injectors when cranking, check for voltage to fluctuate on the ground side at the injectors, then check for voltage fluctuating at the ECU pins for the injectors.

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If that were the case the car would not have done this for the last 3 months in a row lol. The timing has not slip the timing belt is new, under 10,000 miles.

 

Tell me which pins to check the ECU for power if you will.

This car has more grounds than any car I've seen and they are all clean and there are even extra ones somebody put in before i got it...

 

I'm going to read through this PDF download of all of the internal Runnings of this car and find out where that damn pulse signal gets its information from when it has a good working cam sensor and crank sensor the mass airflow sensor is also good there's got to be more in direct link to the ecm sending the ground signal to the injectors.... and I'm not worried about the throttle position sensor, weather bad or good unplugged or plugged in they will not prevent the car from starting they will prevent it from idling normal when they go bad

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My bet is on the ECU being faulty. Open it and check for any moisture. I've seen a number of them die and it's almost always the injector driver's that give out. 

 

GD

Hey general, went over ECu with magnifying glass and reading glasses, it is in fantastic condition and no signs of even dust ever being on it....   I'm trying to upload a picture and a video, someone said I should have a 5 wire ign switch but it's only 4 with a 4 pin plug, and I took a short 5 second video of the cranking and release where the ground pulse to the injector causes the noid flash only after the key is released...

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https://vimeo.com/249961789

 

Here it is, the noid light should flash on every injection which should happen every compression stroke.... 

 

Here's another video, doing it twice, but same results, unfortunately at this time I was down to 11 volts even, and KNOWING this subee, it's started with only 10.5 volts several times recently, but still, the injector signal only happens when the key is released, and I tested the 4 wires on the ignition switch and they're performing perfectly, so I reckon I need to charge up, and find an ECM to borrow and see if that's the culprit the entire time and that it's finally bitten the dust unless there are some tests any of you all can describe for me to follow to ensure it's bnot simply something I'm overlooking or a relay I havent tested yet, which I don't think there are any that cause this specific malady....

 

https://vimeo.com/249962653

Edited by koolminx
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Yeah I still think you need to try jumpering the ignition switch circuit so that it is sending power to the hot in start/run circuit all the time then try cranking it.

 

Also sometimes with these ignition switches.... turn it very slowly till it just barely touches the start contacts. Don't push hard on it, and it might work.

 

The connector pinout is in the FSM you can download from sl-i.net....

 

GD

Edited by GeneralDisorder
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I quite literally did that when I jumped a positive from the battery straight to the starter with the key in the on position back to the off position and back to the crank position with no results to the Noid light or to the car itself other than cranking....

 

Does anybody know which pins on the ECM to probe for a ground sequence for the injectors??

 

It's PDF download really did not help me all that much

Edited by koolminx
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Pin 81 gets voltage only during cranking, so it sounds lile yours os functioning normally.

 

The pins that control the injectors are:

cylinder #1 = pin 2

#2 = pin1

#3 = pin 18

#4 = pin 17

They are supposed to receive 10-13 volts with key on engine off, and 1-14 volts running

 

pin 71 and 72 are injector grounds

 

pin 25, 69, 95, 96, 45, 46 and 70 are grounds

95 and 96 are the ecu grounds, so double check those

 

Pins 15 and 16 are ignition on circuits,

pin 42 is always hot

 

 

 

Odd that you lost spark for a bit...have you just tried starting her on carb cleaner?

Edited by sparkyboy
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Yes I find that Odd as well but seeing as how there are no damaged wiring harnesses and no damage to any of the electrical that I can find I will give the carb cleaner a shot this morning when I go to pick it up with my trailer.

 

I will also do a voltage test to those pins in my ECM

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Most of us know first hand how frustrating electrical problems can be, just keep at it man you'll figure it out.

Make sure you take the intake tube off completely, and hold the throttle fully open when you try to start on the spray.

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