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Misfire Cylinder 3 - possible causes?

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EclipseGSX13

20+ Year Contributor
189
0
Sep 9, 2002
Bellevue, Ohio
I have been having a misfire problem and hooked my palm up to it and got a cel reading misfire in cylinder 3.
It will usually run alright for a few minutes then starts acting up after a little while. It will act up pretty bad at anything over 5 lbs of Vacuum and outside of 2500-3500 rpm's

I have changed my plug wires
Regapped my spark plugs

I still havent solved the problem, what else could be a likely cause?
 
when I had a misfire in cylinder 4 I had 2burned exhaust valves. hope you don't have that problem but mine was hard to start and stayed misfiring. get a compression check done.
 
Yes, get the compr. done you might have a serious problem with knock if that keeps up :)( dont wanna see another dsm go down the pot)

GOOD LUCK!

-Devon-

Have you used any octane booster or race gas??
 
no i havent used any octane booster, i use 94 oct.

I do have a 20g on my car, but slowboy only set the boost at 14 psi.
 
Heres what else I found out:

Its not my coil pack, cause I went ahead and changed that
Its not in my engine, cause it seems to mainly miss when the pedal is more than 1/3 of the way pressed


I think it might be my injectors, that one could be clogged...
What other options are there?
 
If its not your coil, wires, or plugs the next most likely thing would be a clogged injector. Try swapping them around and see what happens. Its only like 3 bolts and the rail comes off and you can just pull the injectors out of the rail and swap them. Dont forget to unplug them first tho.

See what happens.
 
another thing to add,
I did install a A/f gauge, although it was after the problem was occuring.
On the a/f its reading lean (very lean), im not sure if its a related problem or not.

It seems that I could be cause if I had a clogged injector, it would make that cylinder extreamlly lean


I think I will try to swap a couple injectors to see if it makes another cylinder through a cel

I'll let ya know what happens
 
gonna dig this one up from the depths -

I just started experiencing the same problem yesterday. I was on the highway and I stepped on it and I could feel it buck a little...didn't know what to think at first, so I just ignored it. Today on my way home from work it was 10 times worse, the car would buck all the time throughout the entire rpm range.

When I got home and could listen to it idle, I could hear the misfire, feel the car buck, and notice it go VERY lean every time it misfired. I let it sit for 3 hours then took a drive, it got worse and worse. No matter how depressed the gas pedal was the car was very very lean, then all of a sudden the cel came on. Went right home and scanned it, sure shit, cylinder 3 misfire.

Now the car barely stays idle, around 500 rpm...usually 800-900....its a 95 GSX with 103,000 miles on it. I've never had a compression test. Just changed the plugs 4 months ago.

should I just start from square 1 and re-gap the plugs, then change the wires, then the coil pack, then the injectors....etc etc? I don't really want to because this is my only car and replacing all that crap will be expensive! Or just bring it right to the dealership?

Anyone with the similar problem get anything worked out? what were the results? how was it resolved?

Sorry that took FOREVER...had to explain in detail

Thanks!!!
 
oh yeah, forgot to mention...I get like 11mpg now...just burns through the gas like theres no tomorrow...and minnesota gas sucks my balls...10% ethenol
 
a jus to let u kno i had no pressure in cyl 3 and 2... it was a blown head gasket... idk if thatll help or not but that was my prob.
 
I've been haven a misfire show up on and off the last few months. Sounds alot like yours and it was enough to cause a CEL a few times. Happened when it rained usually or humid so I changed plugs and wires thinking it was a arcing wire.. It seemed to work but the other day It seemed like it did it again. I dunno either.
 
to diagnose this problem you should take these steps to save you time and money.

#1 compression check the entire engine.

#2 replace the plugs with a set of cheap copper plugs (champions work fine and are like a bukc). Keep these plugs around so that you have a "known good set".

#3 swap the wires around to see if it is a wire.

#4 (if ya feel like it) pull the injectors and rail and see if they all mist the same (they should all mist for a second when you first go to start the car).

This should show you if you have an air, fuel, or spark problem.

It is rarely the coil because if the coil itself goes out then the paired cylinder will stop firing also (we only have 2 coils and 4 cylinders after all).
 
I just called the Mitsu dealership here and they said they've been getting LOTS of cel's in lately for misfires. They said that a lot of them have been coming from bad gas in the metro area. Since MN gas has 10% or more ethenol. Plus It's been raining here everyday for the last few weeks apparently a lot of water can seep into the tanks ungerground (?). But they said they can run a diagnostics on it to tell exactally where the problem is and that runs $90.00. But they said first thing to do is drain the tank, refil, add water remoevr (Heat or something or the sort), see if that helps. He also said that Iridium plugs can set off the cel....I dont' know about that one.

Also he said to change the plugs and re-gap. Check the resistance in the wires, and add injector cleaner to a full tank. He was pretty confident that fuel system cleaner and injector cleaner would cure the problem.

I'm going to check my plugs again and fill up the tank and add Heat and Injector cleaner right now. I'll update later today.
 
lhhc said:
I'm going to check my plugs again and fill up the tank and add Heat and Injector cleaner right now. I'll update later today.

Use Seafoam. That stuff is the best.
 
ok well the injector cleaner and Heat didn't work. So I pulled the sparkplugs and they looked pretty bad, must not be gapped right because they've seen some intensive heat over the last few months. Theres burned on oil on them and the tips are white...not the tip that *should* be white out of the box.

So I swapped plugs from cyl 3 to 2 and 2 to 3. Started the car...didn't help. Then I unplugged each wire from the coil and checked the ends of the wires and inside the coils....coils looked fine, wires looked like they're on a 95 :) Cleaned them off a little and plugged them back in....started car, misfire gone. Took it for a drive and didn't feel a single misfire. So looks like tomorrow I'm going to put in new plugs, gapped correctly, and get a set of wires. - only thing now is I have a major boost leak, only get like 5-7psi at wot and can hear it dumping out of somewhere....I'll tackle that tomorrow also.

Thanks for all the help...if for some reason the plugs and wires don't help, I'll be back!

Thanks Again!!!!
 
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