cyberkill

I know there's a ton of misfire stories here, and I did read through several long threads (without a solution), but hopefully, this one will be different...

In the chronology of things...
August, 2010
Added headers and e-cutout, works great.
Added TR-55 Iridiums (stock gap), MSD SC wires. Beautiful!
Added a whole new stereo system w/amp and sub, works great....but then after a few months I start getting misfires...

November, 2010
I've never experienced one before. So I'm driving to work one morning on a misty but chilly fall morning, and my whole car starts to shake. My shifter is shaking, I can feel it in the car, feel it in the pedal. I was like...WHOA! I pulled over, turned off the car. Turned it back on, works fine for a week.

Next week, I'm telling my buddy about it and told him I can't reproduce it. Just after I mention it when we go out for lunch, it starts happening. I'm in the middle of an intersection, so I quickly turn off the car, turn on the car, and it's gone again for months.

January, 2011
It happens off an on during the winter, but turn off the engine turn it back on, and it's gone for a long time. I'm praying that one day it'll happen when I'm near an AutoZone so I can get it scanned. One day it actually happens. I pull into AutoZone (leave my car on outside and constantly watching it so nobody steals it) and they pull codes misfire in bank 1 cyl 1. Perfect! Buy another Tr55ix, replace bank1 cyl1 spark plug, swap wires from cyl 1 and cyl3. Week goes by...Misfire! In front of Autozone! Now I get Random Misfire... F!! No more misfires for a while.

February, 2011
It's snowing. Misfire. Turn off turn on. 10 seconds later, misfire! Turn off and on again, great..10 seconds later, misfire! Again, misfire. Again, misfire. Again, misfire! WTF?! Again...ok now it's fine. This is all in the span of about 20 minutes on the highway! Engine is nice 'n' warm too.

March, 2011
Rainy. Misfire. I got pissed. Slammed my foot at the gas, and then suddenly it breaks out of it! Whoa neat! Happens again in a couple days. Did the WOT trick again, breaks out of it! Cool! No misfires for about a month.

April, 2011
Haven't had a misfire in a while, but it was a nice day, decided to go to a carwash. Chillin in the carwash. Water starts. I can feel my car start to shake all of a sudden. Turn off the car for the rest of the carwash. Afterwards, misfire. WOT - it goes away...10 seconds...misfire. Turn off turn on. 10 seconds later misfire. Does this for about 2 minutes, and then it's fine again.

Also, on another nice day. Cruise, no misfires. Mash on the gas, car starts to buck back and forth making me look like I'm headbanging. Try it again, this time, roooOOOOOAAAAARRRRRRRRRRRR-BBRrrrrrr... Right around 3000-3500 rpm it just sorta like acts as if the pedal snapped and is going back to idle. I WOT it again and then it gets to 3000ish and then kinda sputters, headbanging again, and then I'm like..hm... I now have a scanner, so I put the scanner on and now it tells me that bank1 sensor 1 (o2) insufficient switching! W T F ?! ?!? !

I pull over. Turn off the engine. Clear codes. Believe it or not, car runs like new!

Week later, same thing. Misfire. WOT, comes back, WOT, comes back, WOT, comes back, WOT, comes back, turn off turn on, comes back, turn off turn on, comes back, WOT, comes back, WOT comes back, turn off turn on, ok now it works. Also, the sputtering thing is now happening again too. Haven't had a headbanging session lately, but it's like it hesitates. But then if I keep pounding on the pedal, it'll get out of it and run the rest of the RPM range. Also I'm noticing, that on days where I'm misfire free and sputter free, it just doesn't pull nearly as hard as it used to. Something's up!

So I have 2 problems, the sputtering and the misfires. Get this, though, 100% of the super rainy days or very humid and cool days (summer's starting, so I'll let you know how hot humid days go) it misfires. Only occasionally will it happen on a dry day. I'll walk out each day, feel the humidity, and I'll almost have this 6th sense and know that my car will misfire today. On somewhat humid days, after the engine warms up a bit, it'll go away (2-3 minutes). On super rainy days it'll take 5-10 minutes to get the thing to stop misfiring. Once it starts running normal, though, I can park it for an hour in the rain, and it won't have a problem. It may have to do with the engine being warm.

As for the sputtering. NO idea! Friend suggested coilpacks, but wouldn't that be a constant problem?

HALP!

99SSJarhead

iTrader: (2)

o2 sensor most likely. It was probably going bad for some time and the reason you only felt it on chilly days was that the sensor was having more trouble heating up. After a while it stopped mattering that the weather was bad.

I'm not gonna go into details on how o2 sensors work but that'd be the best place to start.

You are probably running very rich which is sending your car into a "limp home" mode when yo can't change from open to closed loop (or vice versa) as the car heats or cools down. When you cleared the code, you took it out of limp home and so it ran fine until the code was thrown again.

Replace bank 1 o2 (i believe driver side before the cat)

therealjcamry

I'm having the same problem, same code. Bought the car in winter, and only if it was wet or it was being washed, it stuttered only for 5 minutes then it would go away. Up until recently I thought it was the humidity giving the car troubles, but I'm getting the O2 code, some one as you. So I'll be replacing that soon, as I can't stand looking like an idiot from stoplight to stoplight with a bucking car, and yeah, its not as quick as it used to be.

On a side note, I used a gumout fuel system cleaner and it reduced the low end bogging to almost nothing. I also cleaned up the MAF like jarhead recommended.

barkerracing59

I have the same problem but its with a lean condition then u feel it misfire bad and the o2 sensor is bad on bank 1 sensor1 so I'm hoping that its the o2 that's causing the misfire and lean condition on bank 1

cyberkill

Oh yeah, after it was happening again, I've cleared the code again, and it didn't do anything...That first time I cleared it, though, was the first and last time I ever got a code about the O2 sensor. In any case, after following a couple threads for a while, I got real worried about the Bosch Corvette O2 sensor (13111 or something like that), sounded like people were getting insufficient switching after changing to those O2s instead of doing extensions. Are they ok now?

Oh by the way, I did extensions on my O2s.

jam01

sounds like you have moisture getting into wiring somewhere, have you checked all your connections?

cyberkill

Sorry for the stupid question but...how do you do that and how do you do it accurately? I've unplugged and plugged all my wires from the spark end and coilpack end, and just pushed on any weatherpacks that I see. I unplugged and plugged my O2 sensors too. Are there other wires I'm missing? Also, I have no Rear O2s, since I have the LTs, so the Rear O2 plugs are exposed. There's no cap on there or anything. Is that a problem?

barkerracing59

today i found all of the wires on bank one werent even put on all the way. so i slid them on tighter and bam no misfire and no rough idle. but i know the o2 sensor is still out so im replacing that but look at your wires

cyberkill

SO...like I said, carwashes cause the misfire.

My friend just got HP Tuners, so we took the laptop and HP Tuner for a little drive through the undercarriage carwash.

My Bank 1 O2 sensor stopped sweeping and went out of range during the carwash and right when we saw that on the screen i started misfiring! We monitored the O2 sensors (Bank 2 was sweeping fine the whole time) and slowly as the misfires stopped, it started coming into range again, sweeping.

So looks like I'm gonna go buy the Corvette O2s. I did extensions when I got LTs, so I might take a spray bottle under the car again and start spraying the weatherpack, the sensor, and the wires to see if I can isolate what it is that's broken, but man I'm so glad I think it's fixed!



Oh, and the bucking and hesitating...While checking things, we checked the air filter and the little weather stripping from the backside of my Lid somehow got torn and was crumpled and all up in my MAF screen! Haven't had hesitation issues during the 15 minute drive home and I'd usually notice it when I went WOT past 3000 RPM, but it didn't happen all the time either, so we'll see how that goes.

joecar

You might find water dripping past the joint in the plastic wiper cover at the rear of the hood (4th gen F-body)...

water drips past the joint and/or under the rubber seal and land on the intake manifold... if you have a vacuum leak under the intake manifold, the water will find it; if your #6 injector lower o-ring has a small airleak, the water will enter there also... this water being ingested may be one of the various possible causes of your misfire.

barkerracing59

It was my o2 sensor the wires were part of the problem but o2 cleared everything up I got Denso sensors they look way better to the stock ones and no more lean condition. It was quick to change out in my drive way even though the motor exhaust and cats were hot as ****

jam01

you check the obvious first, sounds like you found the area that is causing your problems. you could also put the stuff that is used for spark plug boots on the connectors it is supposed to keep moisture out. i cant remember the name of it at this moment. do the 02 sensors first, then move on to the next if that doesnt fix it. and i dont know for sure if being exposed with no caps would do it but im sure it wouldnt hurt putting on them. good luck with it.

cyberkill

I FOUND IT! like...REALLY found it!

(I like stories, so skip down to find out what happened).

<<BEGIN LONG VERSION>>
Now that I knew it was Bank 1 O2 Sensor 1, I was on a mission to find out what about it was broken: The Sensor itself, the wire extension I did, or the connector at the weatherpack. I put the car up on the jack, turned on the engine, and began spraying things with a spray bottle. I sprayed the O2 sensor like crazy and there was no change. I sprayed the weatherpack like crazy and there was no change. I sprayed the extension like crazy, and no change. Pissed off, I started spraying the entire length of the wire sporadically trying to douse it...no change. I took the car off the jack (still on) and tried to reverse it, but then I knew immediately, it started misfiring. Went around the block for about 5 minutes before it stopped misfiring.

Now I was pissed. I wanted to know WHAT caused that misfire. I took the garden hose and put it on Jet. Put the car up on ramps with the engine running, and aimed the jet at the O2 sensor and closeby parts. I sprayed for about 15 seconds, and nothing happened. Drove around the block...nothing.

Then I put it back on ramps, and started spraying the weatherpack (and its nearby surrounding parts), and it started misfiring instantly! Drove around the block for about 5-10 minutes to get rid of the misfire. Now I knew that it was at least on the weatherpack half of the wire.

Put it back on ramps, and started spraybottling the connector like crazy, no change. Then I started working my way back from the weatherpack and sprayed, and when I sprayed 1 specific spot (that was hard to spray the first time with the bottle) it started misfiring right away!
<<END LONG VERSION>>


So...what happened was, 1 small section of my O2 (bank 1) wire was touching the header primaries. I reused the mesh from my old O2s, and you can actually see that it got charred and burned through, but the wires themselves were protected in the heat shielding sleeve. The sleeve was not cracked or burned, but I did notice that if I squeezed the wire, say, around where the sensor was, you could feel all 4 wires, but when you squeezed the part where it got burned, it was like squeezing 1 solid nail. The rest of the wire was fairly flexible, except for that 1 part, and when I tried to bend it, it snapped in half!

So...I went and bought a Bosch 13111 and installed it last night. I routed the wire differently this time so that there's no chance of it hitting the primaries again. The last time, I had routed it in a way where it sort of went over the primaries, but over time, I think gravity brought it closer and closer. This time I'm running it a little differently so that gravity shouldn't have a play anymore. Haven't run through a carwash yet, but I'm pretty certain it's fixed now.

joecar

Cool good job... I like a good ending.

LiquidSword

iTrader: (1)

Nice too see the results. I just did a search on this issue with my car. Time to get under mine and check. By the Way, did your SES Light Flash when this happened? Mine does.

85CamaroZ28

iTrader: (7)

I've actually been having the same prob. Can you elaborate on how you routed the wires so they won't hit the primaries? I've just learned to live with it when its raining or humid. I've changed wires and plugs and switched coil packs and just gave up. I was guessing the only thing would by my o2's. I'm doing headers soon and hopefully I can change the o2's and it'll be over. Glad you got it cleared up man. It always makes you feel better when you fix something. Congrats man.