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Cyl 4 misfire - new plugs


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I was having “in boost” misfires before a bunch of work was done on my car, including new NGK plugs. I am in the process of having an e-tune done and we’re at the WOT in 3rd gear phase and I’m getting a cylinder 4 flashing misfire. Should I go ahead and just replace this coil pack?

Fast WRX has some “close to OEM” coil packs for like $89.

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Are cylinders 2 and 4 on the driver's side of the car? I will switch coil pack 2 and 4 and see if the misfire moves to cylinder 2.

 

Yes, 2 is in front and 4 is in the back by the firewall.

 

Diamond Electric is OEM coils.

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Verify spring inside coil boot is stretched out alittle.

I’ve seen some push back far enough to cause issues in boost. I always verify I can touch them with my pinky before reinstalling.

 

 

Sent from my iPhone using Tapatalk

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Verify spring inside coil boot is stretched out alittle.

I’ve seen some push back far enough to cause issues in boost. I always verify I can touch them with my pinky before reinstalling.

 

 

Sent from my iPhone using Tapatalk

 

 

Can you elaborate a little on what you mean by this? I’ve been reading that these coils rarely go bad.

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Posted (edited)

I will be honest, why are you going to the forums to ask a question about a $100 part? You are having misfires, shits about to hit the fan. Replace ALL 4 plugs (.028) and minimum of 1 coil. How many miles? Have the injectors been replaced and/or cleaned? Have you swapped coils as suggested?

Sometimes you need to pay the $$$ and get the car diagnosed and repaired properly. I am a Master tech, still pay shops to do work I want warrantied....

A few hundred dollars for diagnosis is better than an engine.

Edited by Marvick08GT
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I will be honest, why are you going to the forums to ask a question about a $100 part? You are having misfires, shits about to hit the fan. Replace ALL 4 plugs (.028) and minimum of 1 coil. How many miles? Have the injectors been replaced and/or cleaned? Have you swapped coils as suggested?

Sometimes you need to pay the $$$ and get the car diagnosed and repaired properly. I am a Master tech, still pay shops to do work I want warrantied....

A few hundred dollars for diagnosis is better than an engine.

 

You are absolutely correct! I don't drive this car daily, so I have time.

I did not get around to swapping coil positions yet but I will do that soon. I mainly just posted this thread to see which position No. 4 is in so that I can diagnose which coil may be bad. Not too many mechanics I trust around here, so it largely falls onto me.

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Posted (edited)
Worst case scenario you have another spare. You will need 1! Thanks for the update

 

For sure! Not a bad thing to have a spare of either. I just got to thinking, I'd rather just do this once instead of doing it twice.

Edited by Mr. Electric Wizard
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Can you elaborate a little on what you mean by this? I’ve been reading that these coils rarely go bad.

 

 

Our coilpacks insist of three components.

Coils itself, the boot and spring inside the boot.

 

If you carefully twist off the rubber boot, you will see a spring inside. I typically would remove the spring, give it a few pulls to stretch it out about an 1” from its original length.

Then alittle dielectric grease in the boot to aid the spring back in and it should make a better contact to spark reducing any misfires issues at boost.

 

I’m sure if you look up “wrx coilpack mod” you’ll see some photos or something in that nature.

 

I’ve ran OTL coilpacks after any Oem coilpacks good bad. Claim to be stronger spark, but can’t justify that.

 

 

Sent from my iPhone using Tapatalk

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Still running the coils that came on my wagon, 303,600 miles. You can see the zip tie on my #3 coil below, that's been there since about 2008.

 

DSCN4696.thumb.JPG.39af173767ad3cce698639fc9566c0ab.JPG

304,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.

 

Engine Build - Click Here

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I've heard a bunch of times not to go aftermarket.

 

I run Intermotor on many of my turbo subies when I have misfires. I swear they are a Subaru OEM part in just a plain white box from rockauto. I have never been let down by them.

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Still running the coils that came on my wagon, 303,600 miles. You can see the zip tie on my #3 coil below, that's been there since about 2008.

 

[ATTACH]296051[/ATTACH]

 

Also rocking the original coil packs on my car with 232K and an engine rebuild.

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Still running the coils that came on my wagon, 303,600 miles. You can see the zip tie on my #3 coil below, that's been there since about 2008.

 

[ATTACH]296051[/ATTACH]

 

If you decide you don't want the zip ties anymore, Iwire makes replacement clips for like 15 bucks and you will be back in business. They even have gray and black so you don't mix up front and rear wiring. They are simple to unpin the oem clip and then slide on the new end. They have install insturctions on the website as well.

 

https://iwireusa.com/products/ignition-coil-plug-b

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If you decide you don't want the zip ties anymore, Iwire makes replacement clips for like 15 bucks and you will be back in business. They even have gray and black so you don't mix up front and rear wiring. They are simple to unpin the oem clip and then slide on the new end. They have install insturctions on the website as well.

 

https://iwireusa.com/products/ignition-coil-plug-b

 

Thanks for the info, but I can't see the need to replace the ziptie. I don't remove the wires to change the spark plugs, you can remove the plugs without the need to remove that wire from the coils.

304,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Well, crap. Put the brand new coil pack onto #4 and it's still misfiring.

The car is popping like crazy too when you put the power on.

What could some other possible causes be? Intake/boost leak or exhaust leak? I could try putting another donut on between the downpipe and the rest of the exhaust.

I'm not beyond just taking it to a dang expert either, it's just not super easy to find a turbo subie expert around here (that has free time).

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I've had popping issues in the past from having one bad plug where the ground electrode got damaged and messed up the gap, as well as not placing the coil pack connectors in the correct arrangement. These were from my early wrx days.
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I smell fuel. I think I may have sort of figured out what's going on.

I don't see any fuel remnants anywhere but when I get on it and it bucks a little (no flashing CEL at this point) I start smelling fuel.

I pulled the electrical plug off #4 and it was a little wet. I am thinking now that when in boost, the injector is leaking enough to cause a misfire.

Does this sound reasonable?

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That sounds possible to me. You should be able to get new seals from the auto parts store. Unless its the injector internals that are leaking...

304,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Yep, stock injectors currently.

I decided to just take it to the shop. If diagnosis determines that it's the injector and not just the seal, then I may take you up on that.

I don't want to spend a bunch of money on this current stock injector setup but I also don't want to jump into the top feed conversion yet either.

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