Missfire cylinders 2&3

[dan944]

So this happened whilst out and about.

I'm worried the inevitable has happened before I could even boost her.

Firstly. Are 2&3 the centre 2 cylinders. And not 2&3 In firing order.

Pulled the centre two plugs and both had a tiny amount of wet oil on the washers. This is I think a disaster rom top the oil up ( hope). Very clean oil.
Both plugs were white at the tips and evidently ran too hot.

Gave plugs a quick clean and refitted. Still misfires.

Not finished diagnosis yet but wanted opinions and other things to check in the process.

Oil is between full and low, (with high capacity sump).

Coolant is doing its usual all over the place tricks but there is coolant.

What next. Change out plugs for a set of cooler ones. I have bkr6e's to go in anyway so shall I give it a go?

Engine got hot as hell so think it's running lean as turkey breast.

This all started from taking the battery off for a prolonged period so my guess is that the ecu reset has made it act normal.

[dan944]

Might be out of the brown and sticky. Set up and plugged in emanage.

Uploaded a standard map for now and tweaked the fuelling slightly. Seems to be ok for now. Not misfiring at least :s

[monsi]

Yes 2&3 are the centre two cylinders

You can swap the plugs over that'll rule out any problem with the ones that are in there at the moment.

If it's still missing try swapping the coil packs round and see if it follows them.

If both 2 & 3 are running lean I'd check 1 & 4 too.

After changing the exhaust and manifold are the O2 sensors still connected if so are they mounted somewhere near stock?

Fingers crossed it's something easy



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[dan944]

My afr gauge turned up the day after ordering which is menta as it was due for the  8th.
Which means I'm just waiting for the boss to get welded in so I can fit the wideband and I'm ready for boost. Taken me long enough mind!

[dan944]

Oh dear. It's come back. Was fine until it she warmed up, then started running like a bag of crap again. More diagnosis next weekend me thinks


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[jonbill]

Maybe swap the o2 sensors around and see if the misfire goes to 1&4.

[dan944]

Maybe swap the o2 sensors around and see if the misfire goes to 1&4.

Good shout. Thank you.


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[MrT]

Yes, Dan that is O2 sensor definitely. I had similar problems before due to dodge wiring extensions (not mine...). Amazing how well she runs when it's sorted!

[dan944]

I'm pretty sure it was the o2 sensor. I spliced the sensor wires together and it went away. But I did change a few other bits at the same time so can't be 100%.

[MrT]

What do you mean spliced? Either send 1 sensor signal parallel to both ECU channels or use separate sensors. You shouldn't 'mix' the signals.

[dan944]

Splice 1 sensor to both channels. Lol. My bad.

[MrT]

Ok cool. Phew.