Misfiring camaro
04-08-2018, 05:03 PM
#1
Misfiring camaro I just bought a 2002 camaro ss. It’s fresh out of winter storage and during the trip home it would stumble in sixth gear at low rpm when throttle was applied. If I dropped a gear it seemed to pull ok. I parked it in the garage overnight and when I started it this morning it popped a misfire code. I cleared it a couple times and now it is coming up cylinder 2 misfire. Car starts fine and idles ok. Would bad gas cause it? It’s been sitting for 6-7 months. Not sure if stabilizer was put in or not. Car only has 36000 km so I’m thinking the electronics should be ok?
04-09-2018, 02:03 PM
#2
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Well, you obviously can't know for sure how old the gas is, nor if it was treated prior to storage. But the fact that the misfire code is cylinder specific (and that the car generally starts/idles OK) would lead me to believe that it's not the gas.
Something may be wrong with that cylinder specifically, as the code indicates. The fact that it's a 6-speed car makes bent pushrods more likely (vs. if it were an auto). Do you hear any ticking? Could also be as simple as an issue with the plug/wire on that cylinder, or the injector or coil for that cylinder. Have you checked the #2 wire and plug yet? If no issues there, you could also check resistance (ohms) on the #2 injector and compare the value to other injectors. And you could move the #2 coil to another cylinder and see if the code moves with it.
Something else to consider, is the car stock? If it has an aftermarket cam/valve springs, then you might have a cracked spring. This would be highly unlikely with a stock cam/springs, but some of the aftermarket springs that have been available over the years are known for this issue.
Something may be wrong with that cylinder specifically, as the code indicates. The fact that it's a 6-speed car makes bent pushrods more likely (vs. if it were an auto). Do you hear any ticking? Could also be as simple as an issue with the plug/wire on that cylinder, or the injector or coil for that cylinder. Have you checked the #2 wire and plug yet? If no issues there, you could also check resistance (ohms) on the #2 injector and compare the value to other injectors. And you could move the #2 coil to another cylinder and see if the code moves with it.
Something else to consider, is the car stock? If it has an aftermarket cam/valve springs, then you might have a cracked spring. This would be highly unlikely with a stock cam/springs, but some of the aftermarket springs that have been available over the years are known for this issue.
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strikeone (09-25-2022)
04-09-2018, 02:19 PM
#4
I contacted the previous owner last night and explained what I was experiencing. He filled the car at the beginning of last summer and no stabilizer was used so I’m hopeful that’s the problem (it was out twice).The original code which came up was the generic misfire. After clearing that a couple times it started the cylinder specific code. The motor is as quiet as a new one with no knocks or ticks. I plan on running the remaining fuel out tonight and replace with fresh. I will likely run some injector cleaner as well. If that doesn’t work I was planning on plug, wire, coil replacement.
04-09-2018, 03:39 PM
#6
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I contacted the previous owner last night and explained what I was experiencing. He filled the car at the beginning of last summer and no stabilizer was used so I’m hopeful that’s the problem (it was out twice).The original code which came up was the generic misfire. After clearing that a couple times it started the cylinder specific code. The motor is as quiet as a new one with no knocks or ticks. I plan on running the remaining fuel out tonight and replace with fresh. I will likely run some injector cleaner as well. If that doesn’t work I was planning on plug, wire, coil replacement.
Certainly no harm in trying some fresh fuel first, I agree. But what you've described (and the P0302 code you've pulled) gives me the feeling that something else might be the matter. Remember, beyond the plug/coil/wire it could also be an issue with the injector itself. I also would still not entirely rule out a bent pushrod just yet, especially because it's an M6 and new to you (i.e. you wouldn't be able to know for sure if the car has ever been exposed to severe rev limiter contact or mechanical overrev - those are common causes of bent pushrods).
04-09-2018, 05:51 PM
#7
Your right. At this point I wouldn’t rule anything out. I would be highly surprised if it was internals though. The car was truly used for Sunday drives in the sun. I ran the old gas out tonight and replaced with fresh. I also added a can of seafoam. As I ran the old gas out it would pull hard by times and as the check engine light came on you could tell it was losing a cylinder. Once I refilled the tank it didn’t seem to happen as much. I really didn’t drive enough to be sure. What I will add is I can know let it idle in the garage and it doesn’t automatically throw a code. There is absolutely no engine noise. I also wondered if the injector could have picked up some varnish and is spraying irratically. I will drive this tank of fuel through and see where I’m at. Switching a coil and wire looks simple enough if need be. Pulling the plug out looks like a pain in the butt as there’s not a lot of room. Pulling an injector out looks fairly easy as well.
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04-09-2018, 06:59 PM
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If you're seeing improvement with fresh fuel, that's a good sign. It might very well be some build-up on the injector tip or something like this (and it could be somewhat present on all the injectors, just worse perhaps on #2). If it does in fact continue to be better (but still not entirely fixed) with the fresh gas, then that injector might need a bench cleaning or just a stronger detergent (or ratio) added to the fuel.
04-11-2018, 12:56 PM
#10
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Simplest things first. You really need to pull the #2 plug out and look at it closely. And check that wire, then move the wire, then move the coil.
It is probably nothing internal. Look at plug, wire, coil, then injector. Your problem will probably disappear before you get to the injector.
It is probably nothing internal. Look at plug, wire, coil, then injector. Your problem will probably disappear before you get to the injector.
04-11-2018, 01:34 PM
#11
If you're seeing improvement with fresh fuel, that's a good sign. It might very well be some build-up on the injector tip or something like this (and it could be somewhat present on all the injectors, just worse perhaps on #2). If it does in fact continue to be better (but still not entirely fixed) with the fresh gas, then that injector might need a bench cleaning or just a stronger detergent (or ratio) added to the fuel.
Do you generally have a recommendation for "best" Fuel Injector cleaner? Or does anything really get the job done.
04-11-2018, 02:07 PM
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04-14-2018, 01:35 PM
#13
So I ended up switching coils and wires with no change. I switched injectors around and changed the fuel filter. No change. I finally pulled the number 2 plug. It looked ok. Not really fouled but not tanned either. I put a thermal temp gauge on and could see the #2 cylinder was cooler. I put new plug in and problem went away. Guess I should have started there first. Thanks for any and all replies.
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strikeone (09-25-2022)
04-14-2018, 07:20 PM
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Thanks for the update.
Wonder how that plug ended up failing on such a low mileage engine? Maybe it was always marginal due to a factory defect that just took some time to fully materialize.
Wonder how that plug ended up failing on such a low mileage engine? Maybe it was always marginal due to a factory defect that just took some time to fully materialize.
04-15-2018, 07:29 AM
#15
I’m really not sure. The one thing I noticed about the plug was how crazy the gap looked. It was .080- .085. It must have came from the factory like that. I’m wondering if that large gap would cause a premature failure. Especially combined with bad fuel not igniting. I’m just so happy it’s running great now. I bet it would run even better with some LT’s. Maybe a cam. Haha
04-15-2018, 02:05 PM
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I’m really not sure. The one thing I noticed about the plug was how crazy the gap looked. It was .080- .085. It must have came from the factory like that. I’m wondering if that large gap would cause a premature failure. Especially combined with bad fuel not igniting. I’m just so happy it’s running great now. I bet it would run even better with some LT’s. Maybe a cam. Haha
This makes sense now and it sounds like you've found the problem. I think you'll be fine going forward.
