2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

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Old Jul 19, 2012 | 02:54 PM
  #26  
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From: tulsa,ok.
It's your money, but you can just purchase a leading coil for now to test your theory instead of splurging for a pair only to find out the same thing occurs.
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Old Jul 19, 2012 | 03:39 PM
  #27  
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I just checked the g/y wire with someone turning it over and it does get power off and on as it turns. I found someone with a pair of coils for sale and depending on how much it costs shipped I might just buy both (it never hurts to have a spare if my trailing does work). I'll post my results once I get a new coil on there. Thanks again for all your help.
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Old Jul 20, 2012 | 11:52 PM
  #28  
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Despite my logic behind thinking it's the coil, I was wrong (unless the coils I borrowed from my friend happen to be bad also). I tried a few different things to see if I could find the problem, I hooked the B/Y directly to the battery in case it was something with the main relay, and I checked for 12V before I plugged it in and it was there, then I plugged it in and it was gone again. I held the voltmeter on it while having someone crank it over and while cranking it it went up to a whopping .8V then back to 0 when we stopped. I am thinking maybe it's some kind of drain through the ecu now, since it happens regardless of which coil is hooked up. Any ideas on things that could be sucking the power from the ecu end?
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Old Jul 21, 2012 | 12:36 AM
  #29  
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From: tulsa,ok.
It was mentioned before how you were checking for voltage on the B/Y wire after you connected the plug to the coil. So how are you specifically doing this? Are you pricking the wire w/a pin and taking the reading off of the pin or some other way?
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Old Jul 21, 2012 | 01:02 AM
  #30  
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I had to run a wire for it and I haven't heated the heat shrink yet, so I can get it into the connector right now to check it, so that's where I've been checking. I have also checked it at the junction box before I tried it directly on the battery.
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Old Jul 21, 2012 | 01:11 AM
  #31  
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From: tulsa,ok.
Are you sure the B/Y wire is going to the proper terminal at the coil and you don't have the wires reversed?

And if you take a voltage reading from the battery and use the body of the car as the ground does the volt meter give you a proper reading?

And can you disconnect the spark plug wires from the coils to see if the wires are grounding out the coils.

Last edited by satch; Jul 21, 2012 at 01:21 AM.
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Old Jul 21, 2012 | 11:33 AM
  #32  
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I have tried it with the spark plugs unhooked and had the same result. Unless the connector that goes to the coils has changed at some point then the wires are not switched. I wired them matching the G/Y to the G/Y from the front harness, and the B/Y from the main relay and the connector only goes into the coil 1 way. As far as the accuracy of the voltage readings, I have checked multiple spots using the same ground and was getting correct readings from everything else. If the CAS isn't hooked up properly, or supplying the proper signal, would it be shorting something (and if it's not functioning properly I wouldn't be hearing the injectors click when it's turned over right)?
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Old Jul 21, 2012 | 11:45 AM
  #33  
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I just had a thought that may or may not be part of the problem, the front harness portion I have is from a JDM S5 TII, but the wire colors and positions all matched up with the FSM wiring diagram so I thought it was ok. Could that be the problem/ is there any difference in the wires for the coils on that?
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Old Jul 21, 2012 | 12:23 PM
  #34  
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From: tulsa,ok.
Originally Posted by 13bbuggy
I have tried it with the spark plugs unhooked and had the same result. Unless the connector that goes to the coils has changed at some point then the wires are not switched. I wired them matching the G/Y to the G/Y from the front harness, and the B/Y from the main relay and the connector only goes into the coil 1 way. As far as the accuracy of the voltage readings, I have checked multiple spots using the same ground and was getting correct readings from everything else. If the CAS isn't hooked up properly, or supplying the proper signal, would it be shorting something (and if it's not functioning properly I wouldn't be hearing the injectors click when it's turned over right)?
The CAS would not have an affect on the B/Y wire (and it doesn't run to the ECU). It would affect the G/Y wire but you said you had help to check that and it behaved properly. For the injectors to click the CAS would need to be connected properly.

What you might want to do is to disconnect FEM-02 and see if this affects the voltage on the B/Y wire after connecting it to the coil.

Last edited by satch; Jul 21, 2012 at 12:30 PM.
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Old Jul 21, 2012 | 04:15 PM
  #35  
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Just to be sure, are you saying to unoplug the center plug from the ecu and try it? If so, I see that is for the sensors, but I should still have power to the coils and injectors, so would I be able to start it like that if it does eliminate my problem, or just see if that's the source of the problem?
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Old Jul 21, 2012 | 04:50 PM
  #36  
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From: tulsa,ok.
Originally Posted by 13bbuggy
Just to be sure, are you saying to unoplug the center plug from the ecu and try it? If so, I see that is for the sensors, but I should still have power to the coils and injectors, so would I be able to start it like that if it does eliminate my problem, or just see if that's the source of the problem?
Source of the problem. You want to see if the G/Y is possibly the cause but I doubt is I would be more inclined to believe its a connection/plug problem.

Last edited by satch; Jul 21, 2012 at 04:54 PM.
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Old Jul 23, 2012 | 03:22 PM
  #37  
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I checked without the middle plug in the ecu and still have the same problem. I found someone with a full front harness I've purchased and I am going to try it that way, so it's hooked up the way it would've been in a car, and see if that cures what ails me.
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Old Jul 25, 2012 | 04:35 PM
  #38  
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While I'm waiting for the harness, i was wondering if I could check and see if it's the ecu somehow. I have an S5 turbo ecu that I could swap out but i was wondering if that would work since it's an NA engine? I know it wouldn't work long term, but just to see if the ecu was causing the problem somehow. I figure at this point the only remaining things to check are the harness itself and the ecu, and since I have a front harness coming I'm hoping that's the problem but if it's the ecu I need to source one soon.
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Old Jul 25, 2012 | 04:43 PM
  #39  
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From: tulsa,ok.
The B/Y wire does not connect to the ECU.
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Old Jul 25, 2012 | 05:45 PM
  #40  
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I realize that, but the G/Y wire does connect to the ecu and that seems to be the problem, is something from that end of things (that's why there's no problem until I plug them into the coils and it completes the circuit it loses power). So I figure if it has something to do with the ecu or the harness (since I just got the connectors that go to the coils and wired them myself so I wonder if there is a problem there somewhere).
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Old Jul 25, 2012 | 05:52 PM
  #41  
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From: tulsa,ok.
Originally Posted by 13bbuggy
I realize that, but the G/Y wire does connect to the ecu and that seems to be the problem, is something from that end of things (that's why there's no problem until I plug them into the coils and it completes the circuit it loses power). So I figure if it has something to do with the ecu or the harness (since I just got the connectors that go to the coils and wired them myself so I wonder if there is a problem there somewhere).
But you hooked up the B/Y wire to the coil w/o the G/Y wire and the same thing occured. Correct? And did you ever disconnect FEM-02 as suggested to see if "any" headway could be made?
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Old Jul 25, 2012 | 10:02 PM
  #42  
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If by fem-02 plug you mean the one for all the sensors that plugs into the middle spot on the ecu, then yes I did try that and it didn't work. I never did connect a wire from just the B/Y wire to the coil, I will try that later and see what happens.
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Old Jul 25, 2012 | 10:18 PM
  #43  
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From: tulsa,ok.
Look at post #37. And FEM-02 is located near the ECU and the connector is Orange. It is not directly connected to the ECU.
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Old Jul 27, 2012 | 09:01 PM
  #44  
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From: tulsa,ok.
One thing which was never asked was how did you reconnect the plug from the leading coil to the new wires you had? Did you crimp them or did you solder them?
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Old Jul 28, 2012 | 10:00 AM
  #45  
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I got it running yesterday! I'm not positive what the problem was, because I did 3 or 4 things prior to trying it again, but it's definitely getting a strong spark now and it did start. I stacked all the connectors on the same post as the main relay, disconnected the plugs from the ecu and re-cleaned them and reconnected them, bolted the boost sensor to the frame (I'm not sure if the bracket is a ground like the coils, so this might not have done anything), and also re-did one of my grounds. Thanks again for all the suggestions and help you gave me, I really do appreciate it.
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Old Jul 28, 2012 | 12:01 PM
  #46  
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From: tulsa,ok.
And the crowd roars. ROAR!!!!!!!!!!!!
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