Car misfiring badly. Video included

[spdracr]

So it did this two days ago and it went away and did it again, here's exactly how it happens and I'm gonna describe it with every detail possible.

RPM started bouncing all over the place like it was dancing to the music. Then it started shaking and started idling really really low like it wants to stall and I smelled fuel with a smell of rotten egg. The whole car was shaking violently and I noticed almost a 1 volt drop as well. Let it sit for a while and ran normal after that

we scanned it and pulled code p0421 and p0300. We replaced the coils with an extra used set that I have laying around but I haven't scanned it tonight yet but I will do it within the next hour and I will upload the video as well to give you an idea of what it's doing.

Edit: I scanned it right now and same codes came up

[Malcriaoxx]

wheres the video

[Stewi]

Sounds like what my car did when my TPS sensor went bat-shit crazy.

[spdracr]

I'm on my way home right now I'll upload the video soon

[Malcriaoxx]

Ooo oK I was looking around for a link lol.But that sucks dude my car was acting stupid the other night when the battery wasn't making enough contact.

[mko]

Ill have to say its battery/alternator related

[spdracr]

i tried stewi's idea and borrowed my roommates TPS and it didnt work

here is the video, u will get dizzy watching it lol so just try to listen to it instead, not the best since i used my phone but it gives a better idea of what its doing rather than just reading about it

http://i233.photobucket.com/albums/ee131/spdracr83/th_VIDEO0158.jpg (http://s233.photobucket.com/albums/ee131/spdracr83/?action=view&current=VIDEO0158.mp4)

[keith6110]

It might be just me. But it sounds like I can hear the PCV Valve. I don't think it should be that loud.

[Exhaust power]

I just went down this road like 3 weeks ago. after driving the car for a while tach would go crazy that could be a sign of misfire by the way. Then the car would stumble , run on 2 cyl, burn coil packs . I turned off all my accessorys to run better.

I bought a brand new alt installed it with the battery hooked and killed the battery lol. replaced it under warranty though so had new alt and battery. but problem was still there. Went to my teacher did a battery charging system test every things good but the car cant run at full load(ac, defrost etc) . so he made a extra ground wire from the neg battery cable to the body problem fixed :)

so take out your jumping cables attach it to the neg and to the body to see if you needed a ground!

[spdracr]

Hmm I'll give that a shot tonight after work just gotta find a good grounding spot in the trunk since that's where the battery sits now

[spdracr]

i tried adding an extra ground and it still didnt help

any other ideas ??

[spdracr]

I'm out of ideas guys. Someone gotta have some suggestions

[RedGalant2k1]

Check engine light on yes? Scan it.

[spdracr]

Did you even read the first post Dave ???????

[Exhaust power]

only thing i can say is think backwards right before your problems happen. what did you do to the galant?

[spdracr]

I didn't do anything to it since the headgasket job back in October

[mko]

unbolt the exhaust before the cat and let it hang, see what happens

[mko]

did you check this out?

http://www.club3g.com/forum/performance/55284-how-fix-ses-error-code-p0421-about-5-bucks.html

[Isaurio]

ok all i could say is. Check MAF sensor make sure is plug in or working. Also Check o2 sensors. Wazz up with you RPM niddle?

[Stewi]

unbolt the exhaust before the cat and let it hang, see what happens

not a bad idea at all, could be a clogged cat

[spdracr]

The car is acting like it's running on 2 cylinders, is that a symptom of a clogged cat ??

I mean I'll get under the car and unbolt the exhaust and give it a shot.

I checked that the MAF sensor is plugged in but I didn't swap it out with another one to see if it is bad or not.

Rpm gauge shows that the car is idling at 100rpm or less that's why it looks dead

[SPD_FRK]

not a bad idea at all, could be a clogged cat


I smelled fuel with a smell of rotten egg.
Rotten egg smell is usually directly associated with a clogged/bad catalytic converter. Definitely something worth check out by unbolting exhaust pre-cat and running it.

[Malcriaoxx]

Or just take it to "your" mechanic,if not others would just take advantage of you and try to rip you off

[Isaurio]

If the precat is bad get headers.

[spdracr]

I haven't stepped a foot in a shop in well over 2 years but worst case senario and I can't figure this one out then I will go to the shop that I used to deal with for years which is a well-known honest shop

[spdracr]

it was a bad coil, oddly this started happening before i swapped in those used coils, so i swapped back my original coils, its fixed but i know one of my current coils is acting up so i need to get my hands on another set very soon.

[spdracr]

bump up again, so after i swapped out a newer set of coils from my friends galant that i know for a fact are good coils since he bought them not too long ago, the car started misfiring again. rpm gauge dancing all over the place. we swapped out the reluctor sensors and that didnt make any difference, the more accessories i turned on the lower the voltage dropped. at normal operation it runs at 13.9-14.0v and when i turn the headlights on it goes down to between 13.6-13.2v and with the heat on it drops down to 12.9v and thats when it starts misfiring and shaking and rpm dancing.

we suspected the alternator could be bad and we had a brand new one on the shelf so i replaced that and it still didnt help at all.

im at a loss and i cant connect the dots and figure out whats wrong.

so definitely not a clogged cat since i drove it today for about 50 miles running errands all day and by the end of the day on my way to my friends house it misfired badly that i ran it for about a mile to my friends house on 2 cylinders only

[spdracr]

bump

[SPD_FRK]

Have you disconnected the exhaust before the cat yet to be certain it is not plugged?

[Exhaust power]

bump up again, so after i swapped out a newer set of coils from my friends galant that i know for a fact are good coils since he bought them not too long ago, the car started misfiring again. rpm gauge dancing all over the place. we swapped out the reluctor sensors and that didnt make any difference, the more accessories i turned on the lower the voltage dropped. at normal operation it runs at 13.9-14.0v and when i turn the headlights on it goes down to between 13.6-13.2v and with the heat on it drops down to 12.9v and thats when it starts misfiring and shaking and rpm dancing.

we suspected the alternator could be bad and we had a brand new one on the shelf so i replaced that and it still didnt help at all.

im at a loss and i cant connect the dots and figure out whats wrong.

so definitely not a clogged cat since i drove it today for about 50 miles running errands all day and by the end of the day on my way to my friends house it misfired badly that i ran it for about a mile to my friends house on 2 cylinders only
Thats the same exact problem i stated. and its happening because circuit has a short some where. and one thing im thinking about is your battery location. Its deff a ground or maybe even power. I would go through your engine bay and check for lose grounds. and why not throw the battery up front if it isnt hard for you to do. take some pictures of your battery wires.

I went through the same exact thing cylinder 2,3 and would misfire to the point my coil pack would burn up. That was only when i had the loads on or drove for a wile with some loads on. ended up replacing alt, batt, coilpack for nothing.

and also i went under my car and beat the hell out of my cat cause i smelt what i thought to be rotten eggs lmao

[spdracr]

Spd frk: No I didn't undo the exhaust cuz she came back to life as soon as I replaced the coil the night before and drove it all night with my headlights radio and heater on without a problem. A clogged cat wouldn't magically go away and come back and like I said I have a nasty voltage drop which is causing my misfire issue

exhaust power: I have a distribution block in my engine that has all the wire that used to be on the positive terminal of the battery and a 2ga running inside the car all the way to the battery. My negative is a 4ga or 8ga I'm not positive on that and it's screwed into the inside of the trunk over the tail light

[sponcar]

Missfires means bad spark plugs, bad coils, or bad grounds. Since you bring it back to life after replacing the coils, BUMB you find the problem. Now check for any cut wire in the coils, it may be the problem.!

[spdracr]

But the misfires only happens when the voltage drops and the voltage drop happens when I turn my headlights and heater on or anything that would cause a load on the system. So the question is what's causing the voltage drop.

[mko]

Bad ground or not enough ground, bad distribution block, bad + cable, bad battery

The more load maybe takes away voltage or current away from either ECU or coils that prevents it from firing correctly.

Pull the plugs and inspect the strength of the spark, not the spark plug but the spark itself. Compare between when it misfires and when it runs good

[Ivory8g]

when you turn on electric components does the sputtering misfire get worse? do you burn up coil packs? check the ground cable that goes from the throttle cable bolts to the firewall.

[spdracr]

Ivory what do u mean am I burning coil packs ?? The ground on the throttle cable plate is connected. I wanna change it to 8ga eventually.

I had a lil chat with stewi over texts after I read mko's comment. He suggested I switch my negative wire to a 2ga and choose a different grounding spot. So I think I'm gonna go after that and see what happens.

[Exhaust power]

Ivory what do u mean am I burning coil packs ?? The ground on the throttle cable plate is connected. I wanna change it to 8ga eventually.

I had a lil chat with stewi over texts after I read mko's comment. He suggested I switch my negative wire to a 2ga and choose a different grounding spot. So I think I'm gonna go after that and see what happens.

if you drive wile it misfires enough the coil pack will heat up and smoke/melt.

[Ivory8g]

Yep ^ exactly that

[spdracr]

Well lucky me everytime it did I was getting ready to go somewhere not while I was driving beside the night I posted about it again which was the only time it happened while driving and I drove roughly a mile with it misfiring but that's right before I replaced it with the other coils

[spdracr]

I forgot to update this.

I went ahead and replaced my ground cable from an 8ga to a 2ga like stew have suggested and chose a better spot to ground it and still didn't make a difference

Then I decided to play with the ground cable that goes between the throttle plate and the firewall and that was actually my problem, for some reason it was functioning properly since I installed it about a year ago and now it didn't.

Replaced that with an 8ga cable and now I'm running 13.9v-14.1v with everything turned on.

Now I have an oil leak that I can't trace lol

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