LS2 misfire issue
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10 Second Club
Joined: Oct 2010
Posts: 31
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From: Jacksonville, NC
LS2 misfire issue Alright I've been looking all over a few forums to figure this out but nothing is working yet. I have a misfire/rich issue. I have searched, that's how I've tried what I've tried so far. I'm only posting because nothing has worked yet.
It started when I was driving through town where I am this weekend and there was heavy rain and a lot of huge puddles. I don't know if that was the cause or just a coincidence. Anyway, my idle/cruise AFR went from 14's to 10's and it has even bottomed out the gauge at 9.0 a few times at idle. It idles like it has a small cam in it. It threw a random misfire code and both lean and rich codes for both banks. We hooked it up to hptuners in a parking lot and it just showed all cylinders misfiring a little bit, but mostly cylinders 1 and 3. Randomly it will go back to normal for about 1-2 minutes, then go right back to acting stupid. At higher than idle RPM's, it sounds normal without sounding like there are any misses and drives smooth. I haven't got on it to see if it acts up under load.
So far I've gone through and checked all the ignition wires and connectors going to the coils, replaced the plug wires and plugs, cleaned the MAF sensor, and checked the O2 sensor connectors under the car. Every thing checked out fine and the problem is still there. All I can think of left to check is the o2's themselves or it might be a bad coil or coils.
Besides the o2's or coils, is there anything else I could/should be checking? I'm at a loss here. Not to mention running that rich and having to drive 6 hours to get back to town tomorrow. I'm sure I'll be using at least twice as much gas to get home.
Thanks.
It started when I was driving through town where I am this weekend and there was heavy rain and a lot of huge puddles. I don't know if that was the cause or just a coincidence. Anyway, my idle/cruise AFR went from 14's to 10's and it has even bottomed out the gauge at 9.0 a few times at idle. It idles like it has a small cam in it. It threw a random misfire code and both lean and rich codes for both banks. We hooked it up to hptuners in a parking lot and it just showed all cylinders misfiring a little bit, but mostly cylinders 1 and 3. Randomly it will go back to normal for about 1-2 minutes, then go right back to acting stupid. At higher than idle RPM's, it sounds normal without sounding like there are any misses and drives smooth. I haven't got on it to see if it acts up under load.
So far I've gone through and checked all the ignition wires and connectors going to the coils, replaced the plug wires and plugs, cleaned the MAF sensor, and checked the O2 sensor connectors under the car. Every thing checked out fine and the problem is still there. All I can think of left to check is the o2's themselves or it might be a bad coil or coils.
Besides the o2's or coils, is there anything else I could/should be checking? I'm at a loss here. Not to mention running that rich and having to drive 6 hours to get back to town tomorrow. I'm sure I'll be using at least twice as much gas to get home.
Thanks.
Have you checked your grounds? Made any changes to the car lately?
Check the injectors.
I just finished one that the owner had taken to the body shop.. I guess the shop left the fuel system open so the injectors ended up full of dirt and what looked like ants.
Check the injectors.
I just finished one that the owner had taken to the body shop.. I guess the shop left the fuel system open so the injectors ended up full of dirt and what looked like ants.
Teching In
Joined: Mar 2011
Posts: 9
Likes: 0
From: Sin City
I have the same problem, but cylinder 6 misfire, when i hit a big puddle of water. I can't find the problem either. It will work fine though after a few days of drying out.
Last edited by Sabin SS; Nov 23, 2013 at 04:07 PM.
