2.5 irregular spark

[fishbone]

I put a timing light on each of the wires, and I found a bad miss on #2, and #4 is pulsing a lot faster than the others. #1 and #3 are fine. Could my coil be bad? How can I test it?

Also, someone had suggested that I switch the ignitors to see if the problem goes away. I'm sorta a subaru-noob....what's the ignitor, where is it, what's it look like? : )

 

Thanks for the help, all.

 

--Scott

[subarubrat]

This may sound basic, and you may have already checked it, but if you haven't pull your plug boots and inspect the coil contacts for corrosion. Mine were fine in October of 03, then in Dec of 03 when I was having major performance problems I discovered they had turned green in just two months.

 

Just remember that the Subaru coil is a bit different than most you may have seen. It is a dual coil and if you look at it you can see which cyl are pared. It fires two plugs at the same time, one in the ignition cycle and one that is in it's exhaust cycle, this is called a sacraficial spart. This can throw people and make you think it is firing at the wrong time or out of sequence.

[TheBigJ]

There is a way to test the coil pack with a multimeter as described by the haynes manual. If you want me to type it all up for you, PM me. Otherwise maybe you can get it at the library... or at the parts store.

[fishbone]

This may sound basic, and you may have already checked it, but if you haven't pull your plug boots and inspect the coil contacts for corrosion. Mine were fine in October of 03, then in Dec of 03 when I was having major performance problems I discovered they had turned green in just two months.

 

Just remember that the Subaru coil is a bit different than most you may have seen. It is a dual coil and if you look at it you can see which cyl are pared. It fires two plugs at the same time, one in the ignition cycle and one that is in it's exhaust cycle, this is called a sacraficial spart. This can throw people and make you think it is firing at the wrong time or out of sequence.

 

New plugs and wires, and it's still missing.

 

So with that being said, the left side of the coil should act the same as the right side?

 

--Scott

[lmdew]

Yes, the front or back pair fire at the same time. If you want to try a new coil let me know. I have one. Larry

[frag]

I put a timing light on each of the wires, and I found a bad miss on #2, and #4 is pulsing a lot faster than the others. #1 and #3 are fine. Could my coil be bad? How can I test it?

Also, someone had suggested that I switch the ignitors to see if the problem goes away. I'm sorta a subaru-noob....what's the ignitor, where is it, what's it look like? : )

 

Thanks for the help, all.

 

--Scott

 

Just a thought. Whatch out how you connect you timing light to the plugs wires. On a Subaru engine the wires are so close together that you can pick up the other wire signal on top of the one you're testing if you're not careful. Happened to me. Best to connect near the plugs where the wires are wider apart.

[TheBigJ]

Here is the ignition coil check procedure (in my words) from the Haynes manual. If you havent found it yet, the coil is located where all the plug wires come together (opposite end of spark plug).

 

1) primary resistance check. with engine off, disconnect 3 terminal connector from the coil. Measure resistance across pins 1 and 2 (if you are looking into the connector attached to the coil with the latching part of the clip up, pin 1 is on the right). Then measure across pins 2 and 3. You should get about .62 to .77 ohms - it is ok if your meter says it is a bit higher, because there is some resistance in the lead wires of the meter and in the contact. I think mine came in a bit over 1 ohm (crummy meter).

 

2) Secondary resistance check. Measure from the cylinder 1 plug to the cylinder 2 plug on the coil (these are towards front of car). Then do the same for 3 to 4 (towards back of car). Should measure either 10.4K to 15.6K ohms (hitachi) or 17.9K to 24.5K ohms (diamond). This measurement will not be affected by lead resistance like above.