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Metallman56
08-30-2011, 05:33 PM
i have a missfire on what i think is #3 and i cant figure out why. everyday when i cold start it and back out of my driveway it misfires. it also does it under a engine load, doesnt matter if the motor is cold or hot.

things i have done to fix it are

replaced spark plugs
replaced wires
replaced #3 coil pack

none of these things have worked. i'm starting to think its an injector, but i dont nkow. the car is a 01 with about 125k miles on it. i'm just wondering before i rip half the motor apart and spend $100 on a new fuel injector that it might actually be the cause of the problem.

i know its misfiring because its done the exact same thing before when i needed plugs about 3 years ago. changed the plugs and the problem went away.

also the more i think about it, the more i think it could be about anything. things that it could be in my mind inclued

pcm
fuel rail

and the one that scares the hell out of me would be. . . . . .. timing chain.

any thoughts or help would be awesome


thanks guys


p.s its been doing this for a couple of months now, and at the very begining i threw a code #303. which is a #3 missfire. but sense then i have reset the code and im yet to see the code again. so that why i think its #3.

drakesrevenge
09-04-2011, 01:12 AM
i had a similar problem not too long ago, i replaced the coils, wires, spark plugs. turned out that it was my ignition control module. do you notice if your tach is "jumping" or not?

AaronGTR
09-04-2011, 08:12 AM
Well, you can rule out fuel rail and timing chain. Those wouldn't cause a misfire, and really wouldn't cause a problem at all unless they break. Either they are working or they aren't.

There are a lot of things that can lead to a misfire, but since the plugs, wires, and coils are new I'd probably rule out those. You can't completely rule out the possibility that one of the other cylinders isn't misfiring too though. I've seen cars with random misfires on different cylinders that didn't set any misfire codes. Do you have access to a scanner? Best thing to do would be scan for current misfires and misfire history on all cylinders while driving and see what happens.

But anyway, with those other things eliminated that pretty much leaves the ignition module, PCM, or fuel injectors. Could also be a faulty sensor of some kind with a random glitch that's feeding a bad signal to the ICM or PCM when the misfire occurs. Misfires can be hard to track down.

azr3alazd3ycum
09-04-2011, 10:54 AM
i actually am having the same problem on the same cylinder. this is the second time this has happened to me. the first time it happened i had an injector that ended up in pieces and it caused the rocker stud to break. i am in the process of taking it all apart as we speak to see if it is the same thing as the last time, so hopefully yours isnt that bad.

Metallman56
09-04-2011, 04:28 PM
no tach jumping.

every time i use my cruise in 4th gear, and i either tell it to go faster, or i go up a hill it happens. and when it happens it seems like my car doesnt know weather it wants to down shift, or just stay in gear.

hopefully i can figure it out before winter.

Metallman56
11-29-2011, 10:41 PM
well got new fuel injectors in it, and its fixed. or it was until about 3 weeks ago when i thought it missed again. and sense then its been missing more and more frequntly. i'm pretty puzzled myself. i have now replaced the following.

spark plug
plug wire
coil pack
injectors
pcm
:confused: :confused: :confused: :confused: :confused:

Metallman56
12-04-2011, 10:53 PM
i'm guessing by the lack of responces no one else really knows either, i guess that means i'll have to take it in the shop. crap.

slograndam
12-05-2011, 09:57 AM
u get a check engine light?

juanvan
12-05-2011, 10:12 AM
I would see about replacing the plate the coil pack sit on - that will cause the problems your having.

Metallman56
12-06-2011, 12:12 AM
u get a check engine light?

once. it said missfire #3. i dont remember the code.

I would see about replacing the plate the coil pack sit on - that will cause the problems your having.

correct me if i'm wrong but wouldnt that cause all cylinders to missfire? not just one?

juanvan
12-06-2011, 08:02 AM
.correct me if i'm wrong but wouldnt that cause all cylinders to missfire? not just one?

Nope it can only make one do it - depending on how it went bad

AaronGTR is right though you want to get a scanner on it see what other sensors are feeding out to the system, watch some graphs for a while

slograndam
12-06-2011, 11:52 AM
I wouldn't take it to garage, especially over 1 cylinder. although a lot of things can throw a motor off. Get a scanner, if you lived closer id stop over and take a look.

Metallman56
02-10-2013, 04:44 PM
i'm still having this issue. i cant figure it out of the life of me. all coils have now been replaced. it does not miss for a day or two, then starts up again. the only thing left is that plate they sit on i suppose. what exactly does that plate do?

jonny
02-11-2013, 01:36 PM
i would try the ignition control module.

juanvan
02-11-2013, 01:44 PM
Don't think the ICM is going to cause a miss fire.
But - the crank positioning sensor will, and there is another pulse that controls the Fuel pump that is on top of the engine that could have a broken wire and causing the problem.

HOYS
02-11-2013, 03:06 PM
I had a misfire situation VERY similar to this. Couldn't find the source for an eternity. I NOID lighted the injector in question and it still pulsed but the wire was so degraded that it wasn't putting out enough current to make the injector pulse. New-er injector wiring harness, no issues.

Metallman56
02-11-2013, 04:38 PM
well sense were honestly just shooting in the dark at this point i think i'll start with the cheapest and go from there. when i replaced my injectors i didnt inspect the harness. hell i may start there, becuase i have to do the 3rd lim gasket soon. the crank posistion sensor, and the thing that controls the fuel pump i dont really have to take anything apart.

i'm glad 98% of the time it runs fine, but its really frustrating not to know whats wrong. especially when you spend a good bit of time and money. thanks for the help

AleroB888
02-11-2013, 10:35 PM
well sense were honestly just shooting in the dark at this point i think i'll start with the cheapest and go from there. when i replaced my injectors i didnt inspect the harness. hell i may start there, becuase i have to do the 3rd lim gasket soon. the crank posistion sensor, and the thing that controls the fuel pump i dont really have to take anything apart.

i'm glad 98% of the time it runs fine, but its really frustrating not to know whats wrong. especially when you spend a good bit of time and money. thanks for the help

Could actually be the LIM gasket, but it would help to pinpoint the times of misfire with a scanner. HP Tuners for example, can monitor each cylinder all at the same time and long before they trigger an SES.

HOYS
02-12-2013, 12:05 AM
Intermittent problems usually point me to something electrical :D

Metallman56
02-12-2013, 08:24 PM
Could actually be the LIM gasket, but it would help to pinpoint the times of misfire with a scanner. HP Tuners for example, can monitor each cylinder all at the same time and long before they trigger an SES.

i was also thinking it may be from LIM, though i wasnt sure why that would cause a miss. i didnt the other 2 times. and it just started leaking a few months ago , and its been missing for a lot longer.

my buddy has a scanner that can moniter everything, turn cylinders off that type of thing. it there was a of misses on #3 in the past, but when we took it out hooked up it was #1

Metallman56
08-05-2014, 07:55 PM
well the miss is back. acutally it never went away. LIM gasket was changed, still have a miss. usually it only happens during a cold start, and goes away when I give it a little gas, and doesn't do it again unless its under a load.

this weekend it went exploring in hilly southern Indianan. up almost every freaking hill it missed. bad. like backfired a few times bad. which its never done before. :banghead I could power out of it, but I had to almost floor it, but once it downshifted it was fine.

I don't know wtf there is left to do to fix it. its really p*ssing me off, to the point of selling it and buying some POS that runs right until I can afford the car I want. I don't want to do that, but I'm really out of ideas. I cant just keep throwing money at the damn thing.

plus still no misfire code. how the hell is that possible?

also I checked the catalytic converter, it doesn't glow red at night so I think air is flowing through it fine, but I guess the only way to find out is get a new one, and hope it works like the rest of the parts I've replaced.

any help would be great as always. I'd like to brain storm it for a little while before I get any more parts for it.

thanks as always boys.

sleepyalero
08-05-2014, 08:11 PM
Do the rpms jump up and down on hills?

Metallman56
08-05-2014, 09:04 PM
no. no rpm jump the car acts like it wants/should down shift and doesn't but instead misses/backfires

Metallman56
08-07-2014, 01:51 PM
took a vid this morning in my car of it missing. cold start about 60ish out, it doesn't miss until I put it in gear and reverse it out of my driveway. I kept the camera on the rpms so you guys can see no surge in rpms. missing starts around 25 seconds, stops around 34 seconds. its hard to hear so sorry for that. I couldn't hear the missing on my phone, had to listen on my pc

https://www.youtube.com/watch?v=TmLCUYv4ie0

Metallman56
08-08-2014, 06:45 PM
pulled the front plugs 2,4, and 6 irrc. took some pics let me know what you guys think/see, they all look like spark plugs to me

#2
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_181858982.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_181858982.jpg.html)
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_182342488.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_182342488.jpg.html)

#4
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_182351035.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_182351035.jpg.html)
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_182346867.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_182346867.jpg.html)

#6
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_182757180.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_182757180.jpg.html)
http://i994.photobucket.com/albums/af69/metallman56/Car/IMG_20140808_182801378.jpg (http://s994.photobucket.com/user/metallman56/media/Car/IMG_20140808_182801378.jpg.html)

yes there all e3. I replaced them from delco iridium plugs when the miss started. first thing I changed, still had a miss.

mlog
06-10-2015, 11:30 PM
Sorry to bump an older thread, but did you ever find the source of the misfire?

Metallman56
06-11-2015, 05:08 AM
Nope.

Metallman56
10-19-2015, 10:40 AM
Well I ordered both a crank and cam position sensor. If neither of these work, ill try injectors, maybe. I might just say f*ck it, not sure yet.

sleepyalero
10-19-2015, 01:56 PM
Id replace those plugs from your last pics posted. They look pretty nasty tbh. If it was my car i would

Maybe throw wires at it too.

Metallman56
10-19-2015, 03:20 PM
Both done, neither fixed the issue

Nick-G
10-19-2015, 05:41 PM
Both done, neither fixed the issue

With the same style plug? Those E3 plugs are junk.

Metallman56
10-19-2015, 07:33 PM
Sense the miss i went from e3 to ngk iridium, still have a miss

datashifter
10-29-2015, 07:07 AM
Try some barstop leak pellets. Use the pellets, not the crap in a bottle with the floaters inside. My LIM was replaced and I later developed a misfire when the engine was cold, usually first thing in the morning. Dropped in all six pellets/tabs (about an inch in diameter each) and my misfire has been gone for over a year. Worst case scenario, it doesn't help and you haven't spent much...

EDITED - clarified about the engine being cold, not about it being cold outside.

mlog
10-30-2015, 04:44 PM
Nope.

I had a similar problem, and I threw a lot money buying parts. I'm too embarrassed to list all the parts I replaced. Needless to say there was no fix until I changed the fuel pump. I had long suspected the pump, but it's expensive. I probably had the cost of a fuel pump in the needless parts I replaced. After I replaced it with an OEM pump assembly, it fixed the misfire and hesitation, restored lost power, improved my MPG, and eliminated the frequent hard starting problem. My fuel pressure was only a couple of PSI low on the original pump, but apparently that's all it took. The check valve on the pump was leaky too, and that contributed to hard starts.

Metallman56
12-10-2015, 07:57 PM
so i think i've finally got this miss figured out. there is some reading involved so bear with me.

in november i had to go back home for a funeral. we now live about 275 miles away from where we both grew up. my wife already had plans up there and was coming home monday. the funeral was on a friday and i wanted to drive back home that same day. so we left the night before, planning on getting to my cousins house around 10 pm to crash. about 30 miles into the trip my car started randomly missing. no rhyme or reason, the cruise was set and the RMPs would just spike from 2400 to around 4k just for half a second and go back down. it would only do it once every few mins. but then it started to do it all the time. and it wouldnt just jump to 4k it would jump anywhere from 800 rmps to about 4700 is the highest i saw. backfiring, and smelling like crap. so i pull over. my SES light was flashing (bout time) so i scanned it. misfire #3. sent my wife to the nearest autozone to buy a new plug, new wires, and tools. she came back, and i swapped out the parts. we continued on our trip and it got me to my cousins safely. it did however do an rpm jump 2x after that.

so i went to the funeral and came back to my cousins house. i decided to change all the plugs. i got all of them changed except 1 i couldnt get to with the tools i had, #1 the extension i had was too long or too short, i cant remember which. turned the car on, and it ran like sh*t. so i recheck all the plugs make sure everything is tight, fire it up again, same result, car runs like crap. so now i'm checking all the wires, well one of the wire connects came off of the plug wire. so i take it back to autozone get new wires, and ... still runs like crap. so i put the old plugs back in it, maybe the new plugs are bad. nope, still runs like crap. so i call my mechanic buddy, and limp the car over to his house. so he hooks it up to his crazy scanner. no SES lights, nothing. so he turns off the injectors 1 at a time. each one he turns off the car runs worse. then we get to #3. turns it off, no change. turns it back on, no change. bingo, its got to be injector #3. so the next day (saturday now) i get over there and take of the UIM and take out the injectors. i disconnect all of them except #3 and crank the motor. fuel goes everywhere. not a weak stream but a good working injector stream. so he suggests i take off the back valve cover to check the valve springs, and making sure thats all moving like it should. so i take that all off, and up nothing is loose all the rockers are moving just like they should. finally anther friend brings over a compression gage, and it reads 170 psi. so were good there. so now i dont know wtf to do, neither does anyone else. so i put everything back together thinking maybe something was lose, like an injector wire, and now that i have taken it all apart its like it should be. fire it up and.... still runs like crap. so my buddy hooks his scanner back up to it and turns off #3 injector again. this time the car runs worse. so then he tries #1, and no change. so we pull the plug, remember i never changed that plug, and there is quite a bit of carbon on it. we swap it out for a new plug, fire it up and it runs like new. i dindt know if i should be super p*ssed that was just a plug the whole time, or super happy that my car was running and i could finally go home. so i changed all the plugs, and drove it back home.

after a month i'm happy to report, that the miss is gone. and the car runs like it is supposed to again finally. it feels like a new car. the power i didnt realize had gone missing is back. so if you've got a miss here is what i recommend. NGK spark plugs. they are the only plug my engine seems to like. not E3 not denso, just NGK. ac delco is probably fine to, but from now on nothing but NGK goes into my car.

thanks to everyone for the help, and i hope this helps others figure out there miss. :cheers:

sleepyalero
12-10-2015, 10:41 PM
I suggested replacing the plugs, you said you did, and had no change?

I run NGK as well, and ac delco, just whatever im in the mood for.... Ac delcos are in both my 3400 aleros right now, neither have issues.


e3 plugs imo are junk, i would personally never run them lol

bricooper78
12-10-2015, 10:46 PM
NGK makes the Delco plugs, or did as of a couple years ago

Metallman56
12-11-2015, 01:10 PM
Sleepy plugs was the first thing i replaced. It made no difference between old and new plugs. Actually come to think of it now every time ive had a miss in this car its been the plugs. This would be the 3rd time.

geldartb
12-11-2015, 04:50 PM
there's a plug that runs from the coil pack to the back of the engine block..iirc it's like two twisted wires. have you checked that. it sits pretty close to the exhaust manifold and can melt..

i went through this same **** with my Z26..

sleepyalero
12-11-2015, 07:07 PM
That is the crank position wiring.