Ignition Coil question

[Boneyard]

Greetings,

 

I was poking around earlier, trying to find some information on coils, and I have some questions.

 

My car died the other morning. It started right up, and a few blocks later it suddenly died. I put starter fluid in, but it doesn't seem to get spark. I pulled the coil wire from the distributor and put it up to the frame, but I didn't see a spark.

 

I pulled the coil today and measured everything, and I get about .9 ohm across the contacts (pri. windings, I believe), and 9.96k ohm across the secondary windings (measured from output to neg terminal). I don't know if that would determine that the coil is necessarily good though, just that the resistances are ok.

 

A colleague at work told me that some Subys have a timing module next to the coil (hooked up to the ECU) that can go bad. I am not sure if the one attached to my coil's bracket is that, or just a suppression module for the radio. I am including a couple of pictures just in case. I would also like to know if anyone can tell me if this looks like a replacement coil or the stock one. I would go by the rusted bolts, but every bolt on my car is rusted.

 

Does this sound like it may just be a coil issue? I had a lot of fluid in the engine compartment due to coolant leaks, so it doesn't seem unreasonable that I may have gummed up the electronics. It may just be old as well. Do I just replace the coil, or do I need to replace the module attached to that bracket as well? What exactly is it (the parts store didn't have anything in the system when I called them).

 

Thanks,

 

J

 

92 Loyale, Manual, 1.8L, 230k mi

 

 

[GeneralDisorder]

The coil sounds good from your resistance readings. That's about normal.

 

The ignition amplifier on the coil bracket can fail - it does happen. They aren't cheap - typically those are a dealer item. There are plenty of good one's to be found used though. They are a rare failure.

 

Could also be a problem with the optical pickup in the distributor.

 

When I run into problems like this I try to get a whole set of used bits - coil, amp, distributor, and change one at a time.

 

Of course - check all your fuses and fusible links first. And make sure you have power to the coil and to the distributor. Also - the coil bracket has to be gounded for the amp to work so you have to have it bolted to the body to get spark.

 

GD

[Boneyard]

It doesn't look like I have an ignition amplifier (that's the part I was wondering about). From the diagram in the Haynes manual, it looks like it's a condenser. I think there is some variation depending on the year. Of course I could be mistaken.

 

I'll take the part in tomorrow and show my colleague, but I don't know how much we can glean from a visual inspection. A new coil is only $20, so I don't see any reason not to replace it. Like I said, the spark wasn't coming from the coil wire; I never checked an actual plug wire from the distributor itself. If I still have problems after replacing it, I will start looking at the distributor.

 

Thanks.

[heartless]

yes, that IS an ignition amplifier attached to your bracket.

 

You do need a GOOD ground for that bracket for things to function properly. clean up around the bolt holes, put the bracket/coil back in and make SURE you have good ground (run a secondary ground wire if you have to). test spark again. If you still have no spark then you may need to get a different bracket/ig amp. (also check the things GD mentioned)

 

I had this issue with my 89 GL once - car ran fine one day - got home, parked it - wouldnt start the next day - took me a week to figure out what the heck the problem was - replaced the bracket/ig amp with a good used one - good to go!

 

As GD said - it doesnt happen often, but it DOES happen - finding a good used bracket shouldnt be that hard to do.

[john in KY]

Also check to see if the rotor turns when cranking the engine.

[Boneyard]

yes, that IS an ignition amplifier attached to your bracket.QUOTE]

 

Ok, so I guess the $20 coil is offset by the ridiculous price or unavailability of ignition amplifiers?

 

Why is the amplifier not in my wiring diagram? The connections shown to the coil are to the fuse, the condenser, the SPFI control unit, and the Instrument cluster. It says nothing about ignition amplifiers. When I look for parts, I get nothing for my vehicle. Dealer part?

 

Thanks.

[eulogious]

According to my '88 FSM that has the SPFI in it, the part you are looking for is called the "Power Transistor Igniter". It's connected right next to the coil in the diagrams, so it's gotta be your part. It's for sure in the diagrams in my FSM and it's mentioned when talking about the Ignition Coil. Doesn't have a part number, but that should get you somewhere. Hope that helps ya!

 

Edit: Figured I would quote what the "Power Transistor Igniter" does from the FSM:

 

"The power transistor amplifies the ignition signal transmitted from the fuel injection control unit. The amplified signal is used to make and break the current flowing though the primary winding of the ignition coil."

 

So ya, it's your part

Edited January 8, 2010 by eulogious

[Boneyard]

Ya, brought the part into work. Colleague had a spare coil with the same part (same everything). I am going to hook it up when I get home. If it solves the problem, I will hunt one down. Parts store couldn't find it, said it might be a dealer part.

 

Auto Algebra 101: Dealer part = cost * 2.5. I can always use the spare to get to the junkyard though.

 

It still disturbs me that the Haynes manual didn't have this part in there. It seems like a pretty important part to omit. They left out the MAF as well.

[eulogious]

Ya, brought the part into work. Colleague had a spare coil with the same part (same everything). I am going to hook it up when I get home. If it solves the problem, I will hunt one down. Parts store couldn't find it, said it might be a dealer part.

 

Auto Algebra 101: Dealer part = cost * 2.5. I can always use the spare to get to the junkyard though.

 

It still disturbs me that the Haynes manual didn't have this part in there. It seems like a pretty important part to omit. They left out the MAF as well.

 

Ya, that's why I found a FSM. For $4 more than the haynes, the FSM is WAY better. Try ebay to find one, for sure it's worth the money. I have already found out a WHOLE bunch of info on my car, and I am sure I will find out more info further into the future Hope your borrowed part fixes it so at least you know what it is. Good luck!

[Boneyard]

Ya, brought the part into work. Colleague had a spare coil with the same part (same everything). I am going to hook it up when I get home. If it solves the problem, I will hunt one down. Parts store couldn't find it, said it might be a dealer part.

 

Auto Algebra 101: Dealer part = cost * 2.5. I can always use the spare to get to the junkyard though.

 

It still disturbs me that the Haynes manual didn't have this part in there. It seems like a pretty important part to omit. They left out the MAF as well.

[heartless]

um, haynes - or chiltons for that matter - are not the be all, end all for auto repair - on ANY vehicle.

 

That said - the ignition amplifier doesnt fail that often (just enough to cause headaches for those it happens to) so it isnt something that would "normally" be covered in a general purpose DIY manual. those manuals are for general common repairs...

 

the "spare" you borrowed will most definitely get you to the junkyard so you can pick up one of your own (would actually get 2 just to be safe! lol)

 

another good resource for you would be the "How to Keep Your Subaru Alive" pdf (search for HTKYSA) - informative and funny at the same time

[Boneyard]

Yeah, I usually buy a Haynes manual because it is cheap and easy to read. Usually good for most repairs, as you say. Of course the cloud hanging over my head never lets the repairs be easy.

 

That being said, I am still not getting spark. The coil I put in is probably ok, so I will try getting some wires later and make sure they are good, even though the resistance checked. I checked the Transistor, and there were some funny measurements on mine. I will need a new one anyway, as I broke mine trying to disassemble it. Going to a junkyard, since a new dealer part is $300

 

So if the wires don't do it, then my options are down to either another coil attempt, a distributor, or possibly an ECU issue, right? The alternative to those would be some crazy wiring issue that would pretty much scrap the car and start over. For what I have spent on it in the past month, I'm half way to another car.

 

So to be clear, a distributor problem could cause no spark at the coil if the coil wire is detached from it, right? I get no spark from anywhere that I see.

 

Thanks

[GeneralDisorder]

The distributor serves two functions - first it distributes spark to the right plug via the rotor and cap. Second it has an optical sensor device with a slotted interruptor disc that produces a square wave (5v) signal to the ECU to tell it the posisiton of the driver's side cam, and thus the posistion of the crank. The ECU uses this info to advance and retard the signal that it sends to the amplifier - which is just a transistor that makes/breaks the current to the primary winding in the coil. It's a very simple system but to actually test the distributor's optical pickup you need an o-scope and testing the coil amp is similarly not within the abilities of most people with just a simple meter. But just having a good used set is typically enough to solve most problems. You should be checking for power at the amp and the distributor though to at least rule out power supply issues.

 

The coil is not attached directly to the distributor as in old-style points/electronic distributor's. The distributor is merely another sensor used by the ECU. If the ECU were capable of driving two coil output's then you wouldn't even need a distributor because you could mount up some cam/crank sensors and replace the cap/rotor with a wasted spark coil pack like the EJ's use. But that would require a more advanced ECU and probably one with a faster ECU to accomidate the additional sensor signal and the additional amplifier output for the second coil.

 

The ECU's almost never fail in these cars - I've been here a long time and I've never heard of a confimred case outside of folks that hooked up battery's backwards and blew the ECU power supply (FSM warns against this and that it will damage the ECU).

 

GD

Edited January 10, 2010 by GeneralDisorder

[SHiggins]

Hello everyone,

I've got a 92 Legacy which is only running on clyinders 1 and 2. There is no spark coming from the distribuation coil on cyclinders 3 and 4. Any ideas on what is wrong?

 

Thanks,

Scott

[GeneralDisorder]

Hello everyone,

I've got a 92 Legacy which is only running on clyinders 1 and 2. There is no spark coming from the distribuation coil on cyclinders 3 and 4. Any ideas on what is wrong?

 

Thanks,

Scott

 

Wrong forum - this forum is for EA series vehicles. Your Legacy is an EJ series and this thread has nothing to do with those.

 

You need to post in the new generation forum for Legacy info.

 

Also - gravedigging is not an effective way to get your question answered - this post is now a zombie thread and will attract responses to the original poster's question - even though that neither helps you, nor likely helps them either since this was from months ago.

 

Your problem is either the coil pack or the ignition amplifier. Get a used set from the junk yard and try each.

 

GD