[Whitlc28]

So my 02xe 3.3L started missing on my drive home from work Friday... sure enough the SES light came on. OBD2 says P0306 (cylinder 6 misfire detected).

Heres what I've done so far:

1) Checked for a good spark off the appropriate rotor Cap position. (Looked good)

2) Checked the spark plug wire. (~5.5Kohm similar to no 4wire so I figure it's good)

3) Thought maybe the plug is fouled... replaced all 6 plugs because why not. No change. Note that I was not impressed with the state of the plugs. Just about all of them had some slight oil/grime deposited on them.

4) Tried looking for a manifold leak by spraying brake cleaner and listening for an RPM change (didn't hear any difference though I was not very through and only sprayed a couple spots)

I would also add that the misfire dosent happen until it's warmed up for about 5min.

Anyone else here have to track down the cause of a misfire? What did you try? Any tips would be greatly appreciated.

-michael

 

[shift_RUSH]

Dist cap, rotor, wires, plugs = minor tune up materials.
IFF it was my truck, I'd replace the rest of these items = that you've not yet replaced.
Good luck & keep us posted, please.

 

[smj999smj]

Fuel injectors going bad on VG33 engines is not uncommon. The gallery-style injectors are prone to getting dirt or debris stuck on the screen. Of course, they can go bad electrically, as well. Nissan had a TSB on them recommending using a professional fuel injection cleaning system on them before replacing them. When I got my 03 Frontier SVE, I had a bad #5 injector. Considering it had almost 200,000 miles on it, I decided to just replace them all with reman injectors and install a new fuel pressure regulator while I was there. Replaced the plugs and wires with NGK while the supercharger was out of the way.
That said, if there are more than 60,000 miles on the parts, I would replace the wires, cap and rotor with genuine Nissan or NGK parts, first, and see what happens.

 

[Whitlc28]

shift_RUSH and smj999smj thanks for the suggestions. I swapped out the wires, distributor cap and rotor. Unfortunately the issue persists. My neighbor is convinced that it is a vacuum issue but we have yet to find any bad lines.

The strange thing is that it seems to be intermittent. I left it idling for about 25min. It ran smoothly for the first 5min or so, then started missing. I left it to idle another 20min and it was running fine. I drove it around for another 30 - 40min and it ran like a top. It sat overnight and in the morning I fired it up with the same results (missing after 3-5min of running).

 

[Sabretooth]

You know its like 25deg IDK where you are but you have any little friends around those parts like to stay warm? just a hunch don't cost nothing but go check your engine bay an pull your cover or plenum and check the wiring under there I had to rewire a Camry few yrs ago from them things an another member here just found the same thing little bit ago you might of been lucky an scared him off before he did serious like mine

But if that isn't it
"the misfire doesn't happen until it's warmed up for about 5min."
"It ran smoothly for the first 5min or so, then started missing."

So your until 5min that sounds more like a choke issue IAC also dirty ? but wouldn't cause your 306
Do you have pics of the plugs you changed out an
? did you clear and still getting the 306?
I'd be looking at a leaky injector(fuel getting past valve after shut down) or bad wire to 6injector
If possible pull 6 plug after you let it sit to check for wetness on it

 

[GotToGo]

Swap 5+6 injectors. Clear code. See where code repeats.

 

[Whitlc28]

Update: I figured I would do a compression test on the No.6 cylinder (this was a pain in the A$$) so see if maybe I had bad rings. Unfortunately I couldn't do the test with the engine hot without burning the crap out of my hand so I did it cold and it showed good compression so no ring issues (at least cold). Can anyone comment on how important it is to have the engine hot during a compression test?

Sabretooth, unfortunately I did not take a picture of the plugs, there was some grime on about all of them but nothing major.

GotToGo, I like the idea of swapping the injectors. I think I will tackle that this afternoon. Fingers crossed it results in a smoking gun.

 

[Whitlc28]

Update:

I pulled the manifold off and ohmed the injectors:

1) 16.8
3) 11.4
5) 11.3
2) 11.4
4) 11.4
6) 206.2

This seems like as much of a smoking gun as one could hope for. I'll throw a new injector in No.6 and put everything back together. No.1 is slightly out of spec. (on its way out??) but replacing it doesn't require removing the manifold so I think I will leave it in for now. I did notice that there wasn't any gasket sealer used on the upper manifold. Is this normal? I was expecting to see some.

 

[Hertz]

There should be a gasket there. I would use a felpro paper gasket for that location. Part number MS92273

 

[Mailman]

That injector was even more out of range than mine. Mine was like 30 ohms and would only act up when hot. Hopefully that's your only problem. I've never had a bad injector on anything else before but, I guess welcome me to Nissan.

 

[Whitlc28]

Just wrapped up replacing the injector and putting everything back together. The truck runs like a top again.

Thanks for everyone's input!

 

[Mailman]

Thanks for the update. Glad that was all it was. Why can't the easy ones to get to ever go bad??