Quote:
Originally Posted by jlaguardia
I'm going to try to include an image of the igniter with this post. It is 6 pins going in and 7 pins going out. The additional pin going out is labeled "G" and appears to be ground, as the igniter itself has a metal case, and is bolted to the firewall ("case-ground"). The outgoing wires from the igniter appear to me to split into two groups, one to each side of the engine. Then the wires split such that there are 3 separate connectors on each side of the engine, each connector then connecting to the wires of one coil pack. The coil packs are color-coded, with shorter wires near the rear of the engine and longer wires near the front, so that they can't be confused. There are only 2 wires to each coil; it seems that one is the wire from the igniter (which you have said is switched to ground per signals from the ECU) and the other a positive source, which is not obvious to me even after much tracing, digging, and occasionally swearing. I don't have the manual in front of me, and I'm not even sure if my manual is complete enough to show all of this wiring, but I'll check when I get back home - I'm out of town for a couple of days. If you have a way of posting an image of the wiring diagram you're looking at, please do, if you're willing - it would help future generations of the poor and downtrodden with igniter-related problems. Without an image, I don't think I can find/understand "the second 8 pin plug connector within the loom, which runs from the igniter to the coils" or correctly perform "With the ignition energized you must find and check for voltage at this connector on the plug side at pins 5 can 6, and the black/white wires which become a common connection on or after entering the loom."
Hopefully, there will be an image attached to this post. Thanks again for all your input.
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This has become very confusing but after a lengthy effort things are beginning to make sense.
Your car is obviously different to the wiring diagram I have and does not have the plug in the loom which I have referred to and the positive voltage for the coils as you have correctly ascertained, is supplied via the wire you are unable to trace.
NOTE:
What is more I now find that the connections as shown for the elusive plug/socket connector on the diagram I have (page 6-3 of the 1992 Service Manual, Section 6) are damn and damn it, wrong! It is no wonder that we have become confused as hell :-( In practice the connector has probably not been included for this very good reason! On the basis of your advice I can now make sense of what is the actual correct wiring. :-)
Looking at the 7 pin plug fitting into the igniter, pins 1 - 6 are trigger circuits to the coils, pin 7 is ground but only at the igniter socket via wiring from the igniter to a specific remote ground point, so as to prevent a ground loop collecting interference. Therefore, when measuring between any of plug pins 1 - 6 and ground with the plug disconnected from the exciter, you are measuring a virtual open open circuit, as you have correctly suspected.
In order measure the resistance of each coil, you will need to measure between each pins 1 - 6 and the positive battery supply connection, which will be the wire which you have been able to identify as going to a positive source. With the plug removed from the igniter stick a needle or pin right through the insulation and with the ignition on check that there is full battery voltage. Then
with the ignition off or better still with battery negative disconnected, measure from this same point to each of the six pins connected to the coils in order to read the resistances which will include the connecting wires and meter leads. Make sure you do not hold the needle connection and impose body resistance.
If you find anything suspect you can then remove the coils and check them directly as well as the connecting wiring. You are showing that you understand exactly what is involved.
Man, oh, man this is taking some sorting as the gods have been against us, but a you are saving money as a Subaru agent would probably have told you, "you need a new engine I'll give you a quote". LOL
Patience!
Cheers, Trevor.
P.S. ----
Testing the Igniter after proving the coils and wiring is OK.
You are testing for a square wave output switched in short pulses involving close to 12 volts. The test would best be performed using an oscilloscope or a meter with a bar-graph, as the reaction time inherent in a normal meter will not allow it to properly catch and register very short pulses. However using a normal meter and taking this into account, you should be able to detect a signal while cranking the engine.
You must test for voltage between ground and each of the circuits running to the coils and the test must be carried out with the coils connected and in circuit, so that they provide a return path to battery positive. This makes things rather awkward as you have no exposed points of connection and you will probably have to resort to the needle/pin trick.
Expect to measure pulses of approximately 12 volts DC, connect the leads between each of the leads and ground and with the engine cranking observe for a pulsating voltage. This may not reach 12 volts due to the inherent delay, but will provide a valuable indication that all is well. You are in fact measuring the switching of the coils on and off ground and voltage arrives via the coil when the solid state switch is open.
Test both of the igniters you have and it will not be necessary to bolt them in place as the case ground is not required.
For this sort of work test leads with clips rather than prods are near essential and you should acquire or make up a set. Clip leads are really an essential accessory in respect off a multimeter.