2008 Eddie Bauer EL problems

[rbrtsmith01]

I have a 2008 Eddie Bauer EL that has a problem that is driving me crazy. It has an occasional miss on Cylinder 8. It doesn't do it all the time, and doesn't throw a code. I have replaced all of the spark plugs, coil packs, fuel injectors, and catalytic converters and it still does it. I have done a scan on Mode 6 and cylinder 8 is the only one showing any misfires. I would suspect a valve, but like I said it doesn't do it all the time. Any ideas would be appreciated.

 

[Yupster Dog]

It has an occasional miss on Cylinder 8

Since the symptom is intermittent I don't think that checking with a multi-meter would help.

Check the coil wire harness for Cylinder 8. If you can, while the engine running wiggle the wire to see if you can recreate the symptom. See where it is hanging (might me to close to the exhaust manifold) check the connector itself.
If none of that produces results then switch coil with cylinder 7 and see if the problem stays on 8 or moves to 7.

Come back and let us know what happened.

 

[Keepinitoldskool]

Water could be falling into the spark plug well check for corrosion on the plug nut and replace coil boot if corrosion is found.

 

[Motorcity muscle]

Check the injector on cylinder eight if wiring checks out on coil.

 

[rbrtsmith01]

Since the symptom is intermittent I don't think that checking with a multi-meter would help.

Check the coil wire harness for Cylinder 8. If you can, while the engine running wiggle the wire to see if you can recreate the symptom. See where it is hanging (might me to close to the exhaust manifold) check the connector itself.
If none of that produces results then switch coil with cylinder 7 and see if the problem stays on 8 or moves to 7.

Come back and let us know what happened.

I've replaced the coil and spark plug on cylinder 8 twice, no change. Also replaced the wire plug for the coil pack, no change.

 

[rbrtsmith01]

Check the injector on cylinder eight if wiring checks out on coil.

replaced the injector, but haven't checked the plug on that injector. May try that.

 

[ManUpOrShutUp]

+1 on the wiring. I had an intermittent misfire that turned out to be a small break in one of the fuel injector wires. I initially didn't even find it with a noid light because in the relaxed position, the wire worked fine. When I went back to test it a second time I pulled up on the wire a little, which caused the 2 halves of the wire to separate and the misfire returned.

 

[rbrtsmith01]

Update: Still having the same problem, when it first started it was an occasional miss that caused a slight vibration. However, as the days go by it will keep getting worse to the point that it shakes the entire vehicle. I have discovered that when it gets really bad, if I open the hood and unplug the computer, let it set for 30 sec or so, plug it back up and start the engine, it runs like a brand new one for about a day or so, then it starts missing again.

Not sure if it's the computer itself, or a sensor that I haven't checked.

 

[tommyddsr]

Sounds like a sensor sending incorrect values to the computer. One the computer settles in to the bad values it starts running rough. Pulling the power to the computer resets it to stock average settings. Have you used any software such as Torque to read the computer while running?

 

[rbrtsmith01]

No, I

Sounds like a sensor sending incorrect values to the computer. One the computer settles in to the bad values it starts running rough. Pulling the power to the computer resets it to stock average settings. Have you used any software such as Torque to read the computer while running?

don't have access to that.