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Bad Misfire


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So I was driving and gave it some gas and I get a cel, and then the car starts to drive like crap. It starts up fine, but cylinder 3 seems dead. While it was running I unplugged the coil pack for cylinder 3 and nothing changed so I know something is wrong there.... not sure what. I'm assuming timing is fine cause it starts and runs roughly. So I checked first thing, spark and fuel, I swapped the injectors  and same thing, put in a new coil pack, cause I have 4 news one laying around...., and also changed the spark plug and same thing. So I duno, I didn't hear any bad metal banging or grinding, so I don't think it was anything mechanical. My car got flooded on the passenger side a little while back, so I am thinking it is electrical...... actually praying to god, cause if I have to pull this motor again, I might just move onto something else. Go back to some American muscle.... something with a coyote or hemi... v8s are getting 20 mpg and 500 hp with reliability these days... 

So my real question is, is there an easy way to test my coil pack plug with a multimeter without starting the motor? I hate electrical stuff... The coil pack is 3 wires, I am assuming a ground, power and signal ..... and after that ... blah

Little help! 

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305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

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Iv been searching for a video like this for a subaru, all I can find are 4 wire coil examples. Our subarus have 3 wires i believe, not sure how that works, me and electricity don't work well together lol. 

I'm not even sure if its the coil pack itself, I am thinking its before that and maybe the plug pigtail might be the issue. Cause I tried another coil pack and still dead, could be that the coil pack I had that was sitting around could be dead as well, so I will try a swap cylinder 1 coil. But I was trying to find a simple way to see if the plug is even giving power. Cause cylinder 3 is on the passenger side, and thats the side that got flooded some, so I'm thinking maybe something between the ecu and coil plug might be the issue or something with the harness. But looking at electrical diagrams gives me a headache. 

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I duno whats going on, put in a working coilpack from cylinder 1 and same thing. Used a continuity tester to see if the plug was getting a constant power when the ignition was on, both front and back plugs had the same pin turn on. So maybe its giving power but not the signal to give spark, not sure how I would test that. Car fires right up, but its only running on 3 cylinders..... I have no idea wtf is going on, its not the injectors, swapped those same thing, new spark plug, same thing, coil packs, went through 3 of them...... In all situations I can start the car, sounds like shit, but I can pull the coil pack plug and nothing changes so something is going on there. I hope its not mechanical.... but if it was I would be hearing some bad stuff I am thinking...

Any ideas or thoughts?  Don't be shy! If its electrical...... I may just bring it to the dealership cause I can't deal with that shit...cause i'm about to just pull the coil out, stick a spark plug in it, start the car and see what happens.... if I see the spark plug going off then I know its something else. 

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Easy enough.  To test the injector signal a node light can be used.  Should be able to find a cheap set at Harbor Freight.  Nothing special.  Its just a 12v lamp with 2 metal prongs that plugs into the injector connector.  If it lights up (it will flash/pulse FAST) you have signal to the injector. 

 

To test the coil, once again, Harbor Freight is your friend.  Remove coil pack from engine.  Install coil tester (its basically a glass tube spark plug that allows you to change the gap by threading/un-threading a "bolt") and set gap to about 1/8".  This should be enough to see the spark and prove the spark is strong enough to clear a gap (trying to replicate cylinder pressure and fuel condition). 

 

You will meed a starter button or a friend to turn the key for the coil and injector test.  I hope my simplistic explanation makes sense. 

Edited by m sprank
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Hmm... damn I never even thought about the injector signal/power, just assumed injector.... thank god for more possibilities cause, I really can't deal with a mechanical problem at this point. 

Something like this?

https://www.harborfreight.com/in-line-spark-checker-63590.html

https://www.amazon.com/Lisle-20610-Inline-Spark-Tester/dp/B0002STSC6

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Does not look the same as what I have used for years, but that means I am getting old.  LOL.  You could always use a spark plug with a widened gap as a quick check too.

https://www.amazon.com/Lisle-20700-Coil-Spark-Tester/dp/B00IXMA1RY

 

You got it on the noid light.  One of them will have a pin gap that fits into the injector plug good enough to test. 

 

As you previously have had electrical issues due to water, I am with Max Capacity on this one.  Probably electrical rather than mechanical. 

 

 

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Think I coulda bricked my ecu? After the flood, my obd port wasn't working for a day or 2, so water got to the ecu now that i'm thinking about it. I have an extra one laying around somewhere, I'll try it tomorrow. Waiting on the testers from amazon, should be here Sunday, fell asleep and ordered to late, coulda got em tomorrow. .... sigh, I took my truck off the road to do some long needed maintenance cause I thought the suby was finally working, now i'm carless... these things happen at the worst time. 

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On 9/30/2022 at 2:08 PM, m sprank said:

Does not look the same as what I have used for years, but that means I am getting old.  LOL.  You could always use a spark plug with a widened gap as a quick check too.

https://www.amazon.com/Lisle-20700-Coil-Spark-Tester/dp/B00IXMA1RY

 

You got it on the noid light.  One of them will have a pin gap that fits into the injector plug good enough to test. 

 

As you previously have had electrical issues due to water, I am with Max Capacity on this one.  Probably electrical rather than mechanical. 

 

 

Can you use any of the noid bulbs? Or is there a specific one? 

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Any one that fits. They are all the same otherwise. Worst case take some speaker wire and make an extension, but I always found one that fit Subies.  I had two generic sets and one snap on over the years. All had a lamp that worked.  

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I think I got a valve/timing issue, I posted a video, that tapping isn't to good..... Got spark and fuel.... i don't feel like dealing with this....

I gotta check the timing and pull the valve cover.... not sure what the problem is, just hope it isn't something I need to pull the motor out. Could it be my lashes? Probably should do a leakdown or bust out the borescope..... time to go jump off a bridge.... 😒

 

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Hmmm, I can adjust the lashes without pulling the motor right?? Seems like it would just be a pita, but a hell of a lot easier and cheaper than pulling the motor. 

I'm wondering why suddenly its happening and why it didn't happen from the get go when I first adjusted them? Guess I did a shit job adjusting the valves..... 

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Ummm...  heads/valve train are shim under bucket design.  You can not adjust lash.  You must swap buckets.  Older design buckets had a shim that could come loose and get "kicked out" at higher rpm.  

I have no speakers on my desktop, so I can not currently hear your vid.   

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3 minutes ago, m sprank said:

Ummm...  heads/valve train are shim under bucket design.  You can not adjust lash.  You must swap buckets.  Older design buckets had a shim that could come loose and get "kicked out" at higher rpm.  

I have no speakers on my desktop, so I can not currently hear your vid.   

It's a light tapping sound, not heavy, that's why to me, it sounds like valve adjustment. But yeah, one of the buckets, must have moved or failed ?

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305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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14 minutes ago, m sprank said:

Ummm...  heads/valve train are shim under bucket design.  You can not adjust lash.  You must swap buckets.  Older design buckets had a shim that could come loose and get "kicked out" at higher rpm.  

I have no speakers on my desktop, so I can not currently hear your vid.   

I have b25 heads, I didn't see any shims when I was rebuilding the heads/motor, just buckets. Do the b25 heads have shims? I have a bunch of extra buckets from when I did the lashes last time. Hopefully its just the lash and nothing more serious, I meant adjusting the lash by changing buckets. Will probably check the timing and tensioner as well as try and see if the valves with a borescope, I lost all the adapter fittings so I  can only see straight ahead and the valves would be behind it so it will take a bit of maneuvering. 

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If you did not see shims, the bucket is the "shim".  Each bucket is a specific thickness.  Newer design. 

 

If it is internal, chances are the engine is coming out.  As my 9year old always says, "expect the unexpected". 

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hmmm, that video sounds completely different from the way it was running several days ago when I made the 1st post. I think I might have 2 issues, something electrical and the valve lash. I'm just pissed atm and don't want to look at the car so I will get at it tomorrow. 

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3 hours ago, m sprank said:

I have no speakers on my desktop, so I can not currently hear your vid.   

Oh yea, and what are we in the 20th century? No speakers for your desktop? Come now, let's be civilized! What are we barbarians? No smartphone? 😛

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I am showing my age, lol.  My new 5g smart phone has the slowest internet connection since dial up. I keep my old S7 around just to use for internet.  I work from a home office and my work phone is an old iPhone 5. My laptop has a 14" screen, so it worthless except for email. I use a leftover Windows 7 desktop from my shop (8 yeats old?) for everything else. I have a spare desktop waiting if this one dies. Lol.  But with only so much room at the desk, I never hooked up speakers.  I dont watch anything on a computer  so it rarely bothers me. I like the internet silence.  

 

I am fallimg behind on tech.  But your 4th gen LGT is not getting any younger or tech savvy either.  So I suppose it matters not.  My next car will be carbureted.  My next bike will be a 2 stroke.  My next truck might have a steam engine. 

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.....  your 9 year old is right. More i'm thinking about it the engine is gonna have to come out.... cylinder 3 is dead and has spark and fuel, so its either a valve, or my rings which are letting everything blow by, but a ring wouldn't make that sound, and the tapping points me towards the valves... maybe I burnt or bent a valve? If thats the case, it will probably happen again i'm assuming... My turbo doesn't sound like its hurt or sound like a piece of shrapnel hit it. What else coulda happened... snapped my camshaft or valvetrain exploded .... who knows... gotta put this on the back burner while I get my truck back on the road. 

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