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Miss-fires only when its cold & rainy out?

5332 Views 33 Replies 12 Participants Last post by  Cologne, 
Cologne
Sounds odd but when its raining and cold outside my engine missfires pretty bad when I step on the gas. Runs like a champ on nice days. I cant figure it out.

Ive swaped out most everything.

Any iders? :roll: :lol:
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Cologne


I just changed out my plugs and found the driver-side front plug totally caked up. It was pretty bad. White cake. I don't think I even had 10k miles on these plugs. ? I never seen it so bad on the other plugs Ive tried. All the other plugs were fine. Just this one was real bad. What is it telling me? Am I burning oil? I do get white smoke when I stomp on the gas. But I never get check engine light and it passes inspection.

I don't even know why it only miss-fired so bad when it was cold and rainy. ??????

It runs great now.

This plug is a IRIDIUM! Not good for old engines I guess. lol.
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D
By the looks of that plug it seems you may be running lean .Could also be oil or carbon buildup but I would think the deposits should be darker
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Cologne
davesyo said:
By the looks of that plug it seems you may be running lean .Could also be oil or carbon buildup but I would think the deposits should be darker
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yeh... Its just the one cylinder that does this. But Ive never seen it this bad. It musta been acting like a glo plug. lol :banghead: :banana: :layrubber: :noflame: :tease:
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Matrixx
Hi Cologne
I run OEM Cap and Rotor always now, but I run the Iridiums (Tr55-IX (Like yours)) with no problems at all. My motor has 500,000 kilometers on it and just passed Air Care with better readings with the Iridiums than the Bosch's or Delcos. I don't think this is an Iridium problem by the looks of it. Do you use any kind of anti-seize or grease on threads before installing them? That would explain the black on the first 2 or 3 threads that go into the cylinder? If this has been a problem in that cylinder for awhile then you really need to the basics first on it. narrow the miss to a cylinder first an foremost (more than likely will be #1 by the looks of it) but make absolutely certain it is. The #1 wire is the longest out of the bunch and requires more power from the coil to light that one off, Make sure you have a strong Blue spark from both the Coil to Cap and from the Cap to the wire. How were the threads in that cylinder? Any problems installing or removing that plug? If everything checks out, then start looking at a sticking Poppet that can cause a "cold start injector leak". Try running some premium gas for 2 or 3 tanks to see if that will clean it up. I would recommend Chevron as it is a Top Tier rated fuel and what I use myself. I don't recall anything hooked up in the way of vacuum lines in the intake galley to that cylinder but don't quote me on that. Just check and make sure if there is, make sure you don't have any vacuum leaks relating to that cylinder. Hope something here helps cologne, because by the looks of it will happen again if you didn't damage that plug in the first place. Please keep us updated, Thanks.

PS: Hmm, What type and weight of oil are you running cologne? In Very rare cases it could be a bad valve guide seal or the wrong viscosity of oil being used that will allow the it to Seep by the seal into the cylinder. Just a thought.
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Cologne
Matrixx said:
Hi Cologne
I run OEM Cap and Rotor always now, but I run the Iridiums (Tr55-IX (Like yours)) with no problems at all. My motor has 500,000 kilometers on it and just passed Air Care with better readings with the Iridiums than the Bosch's or Delcos. I don't think this is an Iridium problem by the looks of it. Do you use any kind of anti-seize or grease on threads before installing them? That would explain the black on the first 2 or 3 threads that go into the cylinder? If this has been a problem in that cylinder for awhile then you really need to the basics first on it. narrow the miss to a cylinder first an foremost (more than likely will be #1 by the looks of it) but make absolutely certain it is. The #1 wire is the longest out of the bunch and requires more power from the coil to light that one off, Make sure you have a strong Blue spark from both the Coil to Cap and from the Cap to the wire. How were the threads in that cylinder? Any problems installing or removing that plug? If everything checks out, then start looking at a sticking Poppet that can cause a "cold start injector leak". Try running some premium gas for 2 or 3 tanks to see if that will clean it up. I would recommend Chevron as it is a Top Tier rated fuel and what I use myself. I don't recall anything hooked up in the way of vacuum lines in the intake galley to that cylinder but don't quote me on that. Just check and make sure if there is, make sure you don't have any vacuum leaks relating to that cylinder. Hope something here helps cologne, because by the looks of it will happen again if you didn't damage that plug in the first place. Please keep us updated, Thanks.

PS: Hmm, What type and weight of oil are you running cologne? In Very rare cases it could be a bad valve guide seal or the wrong viscosity of oil being used that will allow the it to Seep by the seal into the cylinder. Just a thought.
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Thank you for the info. I really appreciate your time. :lol:

Yeah, I think that cylinder is taking a dump. I use 5/30 oil I think. Some 10/40 too if thats all I have. I always run 92 octane. $72 to fill the tank this week. OUCH!!!!

I thought a bad valve guide seal only smoked at start up. And rings only smoked on stomping on the gas. And Blown head gasket blew bubbles in radiator or sucked and burned coolant? I smoke on acceleration so I don't think its valve guide seals. Dunno.???

Its running great now but I'm going to have to change that plug out when I get miss fires again.

Geeze dont wanna pull a head.
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Matrixx
Hi Cologne
Thats no problem, I do what I can to help when I have the time and something to add. If it's running fine now Cologne then my suggestion would be to try a different gas station like Chevron for your fuel. If it is Chevron, then I would suggest you try to balance your weight of oil out to 10/30 on a regular bases (I run Castrol 10-30/ 2-Quarts Regular - 2-Quarts Castrol Syntec). Maybe try that out and see if it settles down a bit. $72.00 for a fill up? Wow, I pay over $100.00 for my fill ups, I sure wish I could get your rates, and that's a sad comment to make, $72.00 is ridiculous and $100.00 is just Insane (Rant Off). I hope you get it sorted out cologne, please keep us updated, Thanks. :)
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Cologne
Thanks. OK. :bigsmile:
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G
I had the same issue and cap & rotor didn't help. Then I pulled the dog house on a cold and rainy day, cranked the engine, and heard an arc. I look in there and there was an arc jumping across the top of my coil. I replaced it and that fixed it.
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Cologne said:
Sounds odd but when its raining and cold outside my engine missfires pretty bad when I step on the gas. Runs like a champ on nice days. I cant figure it out.

Ive swaped out most everything.

Any iders? :roll: :lol:
Click to expand...
Not sure if what I just went thru is your problem.. but it sounds pretty close. I have a 98 GMC Sonoma 4.3 vortec 4x4. I was experiencing a very bad "stumbling" if you will, between 1000 and 2000 RPM. never on idle or acceleration in neutral. But when I was going down a road and in between those RPM's. it would fall all over itself. Not doing this if accelerator pressed or if let off accelerator. only when barely pressed to maintain speed. Also, it was absolutely HORRIBLE after it rained and was cold.

anyway, long story short. it turned out to be my Throttle Position Sensor -Which threw NO CODE WHATSOEVER- I replaced with a new one and VOILA.. runs beautiful again.

I do agree with everyone else tho. check plug wires and cap first. But also, the TPS was only 30 bux....

Just something for ya'll to think about...
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Cologne
Thanks thats good to know. So far Im still running great. Im thinking that plug might of been cracked too er sofin. Explaining the cold wet wether.

Im gonna remember what you mentioned because that part is probably due next. hahahaa
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K
Well after I fixed my mis fire with the spark controler in the dist cap I got some nasty backfires into the intake. It started off only in the rain and then got to the point of backfiring all the time. If you took the dog house off and went for a drive at night to look for sparks nothing would happen and the van ran like a champ. After changing the MAF, O2, TPS, and checking the adjustment on the idle sensor as well as adjusting the shift points in the trans. I finally figured it out the leads were bad and were shorting against the tinfoil on the inside of the dog house and sending spark to different cylinders and causing massive back fires into the intake. (by the way that is really loud when you have the air cleaner off and the dog house removed) After new plugs and leads it is much happier.

On a side note as a result of the backfires I had to go and put on some new muffler clamps as it blew the muffler back off the cat convertor and I was running open exhaust on the way home from work the other day. :layrubber:
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Cologne
Yeah... That happened to me too along time ago. I found it because the foil on the doghouse had black burn marks.

We can send a man to the moon and clone people but we still cant make good parts. lol! :confused1:
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Cologne said:


I just changed out my plugs and found the driver-side front plug totally caked up. It was pretty bad. White cake. I don't think I even had 10k miles on these plugs. ? I never seen it so bad on the other plugs Ive tried. All the other plugs were fine. Just this one was real bad. What is it telling me? Am I burning oil? I do get white smoke when I stomp on the gas. But I never get check engine light and it passes inspection.

I don't even know why it only miss-fired so bad when it was cold and rainy. ??????

It runs great now.

This plug is a IRIDIUM! Not good for old engines I guess. lol.
Click to expand...
Your plug wire was not on all the way. That is a tough one to get to with the damn heat shield in the way. Remember to hear the "click" or it ain't on all the way
.
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Cologne
Hmmm yuh know that would seem to explain the problem when its cold and raining. Water or moisture musta been getting in the boot.

Thanks for the info. :grinning:
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