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Post by justyrobo on Feb 6, 2017 19:07:45 GMT -5
My 89 gl was not running when I bought it. I have been diagnosing a no spark issue. Getting power and signal up to the coil, but no spark after (ruled out timing and dist problems by running coil output directly through spark tester to ground). I put in a new coil (and cleaned up all ground contacts), but still the same problem.
I am interested in the signal amplitudes now. The igniter is getting above 11V on the hot line, and a negligible amount of resistance on the ground line to battery, so power and ground seem fine. Ecu line (to igniter) starts at 2V when the ignition is turned on, and then jumps to around 2.5V when cranking (manual says to alternate between 2-7V). I think my analog meter is just too slow reacting to pick up on the pulsing, and just shows a duty cycle average. I am not sure what the other line (tach) is supposed to be doing.
What I am most interested in, however, is the leads to the coil. Power line still sees the same 11V+ as igniter, but the signal line starts at 12V when ignition is on, and drops to ~10V while cranking (when back probing the connector). I almost expected the result to be the opposite, 0V while ignition is on (no spark) and then 12V pulses while cranking (send power into the coil when ready to spark). I know the coil has a ground lead on it, so my thinking may be wrong.
I have already gone through the troubleshooting guide in the FSM a few times. The distributor resistance looks good, new dist cap/rotor, new plugs/wires, new coil. The harness from dist to ecu is not broken (resistance check), and the harness from ecu to igniter checks out as well. Power and ground to the ECU are good as well. I am looking at the igniter now for possible fault.
Thanks in advance, looking forward to getting this bright, sunshine yellow justy back on the road!
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Post by certimafied on Feb 6, 2017 19:38:01 GMT -5
I read your post a couple times but am not sure still. Are you getting spark out of the coil? or no spark at all? I've had my rotor button, little piece of carbon in center of dizzy cap, disintegrate and disappear before. Unfortunatley I cant answer your other questions, but could throw you my two cent lol.
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Post by justyrobo on Feb 6, 2017 20:35:29 GMT -5
Appreciate the reply. No spark at all. Really stumped right now with this one.
I dont' like to rule things out. Perhaps the spark tester gap is too large, or the ground circuit is getting restrictive due to age and rust. But I have cleaned all the grounds I can and made sure to test things repeatedly for good results. No spark yet, but power and 12V signal to the coil pack.
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Post by certimafied on Feb 6, 2017 21:04:34 GMT -5
Ok I get you now.
The coil should have 12v on one side and then its the ignitors job to make and break the ground signal on the other side of the coil to create the spark out of the large center post. You can try checking to see if the ignitor is making and breaking the signal to the igniton coil with a test light. Put one lead of light on battery positive and the other lead on the negative post of the coil, you should see the light flash every time the circuit is made and broken.
I have a feeling that you wont see that, in that case I would check the wires in the harnesses. I know you said you have checked the resistance of the wires but have you checked to make sure that they dont have continuity with each other. Its not unheard of for the insulation on wires this age to crack and fall off, maybe inside the harness somewhere some of the wires have bare spots and they are touching each other mixing up the signals. My justys wires coming from the distributor had this going on.
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Post by justyrobo on Feb 6, 2017 21:27:00 GMT -5
These are good ideas. For verification, the negative post is the ground strap attached to the underside of the coil? So everytime the transistor is active power from the battery flows to ground. I don't have the continuity ability on my cheapo multimeter, but I am going to borrow a fluke and check for continuity.
It may take me a bit to post back in here. Sunday to get the fluke, and then time to run diagnostics. Will update when I have news. Thanks for the ideas!
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Post by certimafied on Feb 6, 2017 21:36:51 GMT -5
I think your justy has a different coil than mine, so hard to say. There usually is a positive post with 10-12v from the ignition switch and a separate negative post that is connected to the ignitor to make and break the ground connection. If you cant get a continuity tester you can use your ohmmeter, your meter should not be able to read anything between the wires if all is good. Though the continuity feature on a meter makes the job go quicker. No problem I hope you figure your problem out, good luck!
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Post by certimafied on Feb 6, 2017 21:43:10 GMT -5
I think your justy has a small kind of square shaped coil right? if so then the two "posts" im talking will be the two wires on your connector going to the coil, and the big "strap" your talking about is a mount/heat sink for the ignition coil. Sorry my justy has a slightly different set up.
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Post by justyrobo on Feb 13, 2017 20:02:08 GMT -5
I hope the image above goes through. Getting errors when trying to upload, and the preview option is not working. drive.google.com/open?id=0B1_JmAyfvqThOGw3UTlQRUVqVDQ in case the pic does not work (this is my ignition coil and igniter). Anyways, sorry it has been a few days. Got around to doing some tests today. But first, clarification: the igniter is a small square box with a black heat sink on it to the right of the coil pack (when looking at the engine bay). it has 4 leads to it from the harness, and then has 2 leads going to the coil (plus 1 ground wire on the underside of the coil back to the igniter). only 3 of the 4 lines from the harness matter (one I believe is TACH output to gauge cluster). I got the fluke and measured the resistance of the pickup coil in the distributor. I pulled the cap and rotor off, and then pulled the internal plugs off and measured about 1050ohms across the coil. I also checked (from the internal wires when they were disconnected) for continuity between the crank angle sensor wires. They had no connectivity. The crank signal goes back to the ecu, which outputs the signal to the igniter. I pulled the 4 lead connector from the igniter. The signal line had no connectivity with any other line, but the power and ground lines have connectivity with each other (even when the battery was fully disconnected and all 3 ECU plugs were pulled out from the ECU). I see no reason for those lines to be connected, as the power comes from the ignition switch (the key was removed at the time of testing, so it should be open circuit). However, with the ignition turned on, the power pin shows 12V and the ground pin shows 0 (referenced to battery ground). So I don't see a short anywhere, and am quite confused by that. The test light from battery ground to coil ground (the ground wire between the coil and igniter) is always lit. There was no pulsing, as you predicted. I am not sure if the igniter is burnt out or not getting the signal to cut ground. But this would be the reason that the secondary coil is not firing. So just to recap data: - crank angle sensor seems good. No cuts/interconnect between the lines, and the pickup coil reads 1050ohms. - Ingiter is getting 12V power, and good ground. It is also getting (when ignition is on) 0.285V on the signal line. - Coil is new, good ground, and receiving the same 12V and 0.285V signals that the igniter is. At this point I still think the igniter is to blame. But I don't see anywhere to purchase them.
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Post by certimafied on Feb 17, 2017 21:02:31 GMT -5
I would agree with you, the ignitor does sound like the culprit. Not sure what could be up with that continuity test reading there must be something else on that circuit allowing back feed. Good luck in your search for an ignitor, I've had pretty good luck getting a few parts from a local subaru dealer fast and a decent price.
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