At a loss- Cylinder misfire
#1
Registered member
Thread Starter
Join Date: Nov 2004
Posts: 6,252
Likes: 0
Received 0 Likes
on
0 Posts
At a loss- Cylinder misfire
Background 2003 Infiniti G35 MT6 Coupe. ~130k miles.
Problem: Car has a miss on the center cylinder on the drivers side. This miss developed slowly over the period of a week. I changed the plugs in the hopes that would fix it and it netted me no result. Letting the car run a bit netted the cat get glowing red hot. This is probably due to un-burnt fuel finding its way into the exhaust (The plug on the center plug smells like fuel fyi)
Diagnosis: I discovered it was this cylinder when I pulled all the plugs and realized that one was covered in oil/fouled. I then proceeded to check other things.
Things I've done
1.) Compression test. 195-200psi across the board.
2.) Removed injector. Battery tested it, (clicking), back flushed it.
3.) Replaced coil 2x. Bought a used set of 6. No change when switching out.
I'm at a loss. Only thing I can think after dicking with it is that I somehow lost the cylinder (mechanically). Would a compression test not reveal that?
Anyway, TIA.
Problem: Car has a miss on the center cylinder on the drivers side. This miss developed slowly over the period of a week. I changed the plugs in the hopes that would fix it and it netted me no result. Letting the car run a bit netted the cat get glowing red hot. This is probably due to un-burnt fuel finding its way into the exhaust (The plug on the center plug smells like fuel fyi)
Diagnosis: I discovered it was this cylinder when I pulled all the plugs and realized that one was covered in oil/fouled. I then proceeded to check other things.
Things I've done
1.) Compression test. 195-200psi across the board.
2.) Removed injector. Battery tested it, (clicking), back flushed it.
3.) Replaced coil 2x. Bought a used set of 6. No change when switching out.
I'm at a loss. Only thing I can think after dicking with it is that I somehow lost the cylinder (mechanically). Would a compression test not reveal that?
Anyway, TIA.
Last edited by RandomTask; 10-02-2011 at 03:41 PM.
#2
Racetracks
Join Date: Nov 2002
Location: How long is a piece of string?
Posts: 15,668
Likes: 0
Received 0 Likes
on
0 Posts
Re: At a loss- Cylinder misfire
It sounds like they're coilpacks, so have you tested the signal at the coil and that the coil has power and a decent ground?
#3
Registered member
Thread Starter
Join Date: Nov 2004
Posts: 6,252
Likes: 0
Received 0 Likes
on
0 Posts
Re: At a loss- Cylinder misfire
Figured it out. Two coil connectors were switched. I get tard of the year. Although, the way the harness is setup, it makes you have to cross the leads off the main (so all the other coil connectors come straight down from the harness, these two run in a X). Runs great sans the now probably shot cat. (I know the O2 sensor is at least toast)
Thread
Thread Starter
Forum
Replies
Last Post