Teal2nnr

iTrader: (7)

I was driving home one night and the car started to have a bad misfire, just out of the blue. I pulled the car over thinking something may have been disconnected, but when I checked everything out it looked good. I waited 10min tried starting it again, it started fine so i drove off. 15min later (the drive home is about 20) the car starts doing it again so I stop, wait, start it up and drive off again. This happened about 4 times progressively getting worse until I got it in the driveway.

The car has a sparktech CDI COP on it, so I figured maybe one of more of the coils had overheated since I just put a ignition coil cover on that day and it was pretty hot outside. So I ordered 3 new coils from sparktech and installed them (I thought some of the old coils should still be good).

Fast forward to last night, I installed the new coils started the car up and it still had a miss on idle. I waited a couple minutes as the car was still idling and it seemed to clear up. I took the car around the block and BAM! it starts misfiring again. So this morning I put the stock coil packs back on, start the car, and it idles fine. I pull out of the driveway thinking I have narrowed down the issue, I get out onto my front street and it starts misfiring again.

So my last thought is maybe its the plugs? They're not old and barely have any Km's on them, but that's my last idea. Is that something people have ran into before with bad plugs? I had them out and they aren't dirty or damaged.

The car is pretty heavily modified AEMv2...etc and barely gets driven, so its pretty frustrating running into an issue like this. Any advice would be appreciated.

TL;DR The car developed a missfire out of the blue. It got progressively worse on my 20min drive home. The car will idle ok but misfires under light throttle on both stock and aftermarket coil packs. The spark plugs aren't old and when I inspected them they looked ok. The last thing I'm going to try is to swap out the plugs, but if that doesn't work i'm not sure what else to try.

Teal2nnr

iTrader: (7)

Nothing? Im thinking CPS so im going to change that out and hopefully that resolves the issue.

Ev0ikon

iTrader: (18)

What plug gaps are they at?

Teal2nnr

iTrader: (7)

They're gapped low at .020. With the sparktech i should actually raise it a bit. But it ran fine before, just out of the blue started misfiring.

J_Striker

iTrader: (4)

What does your fuel look like? Meaning, take loose a fuel line, try and start the car a few time and collect the gas in a glass jar. Let it sit and see if there is water in it.

Teal2nnr

iTrader: (7)

For anyone that has similar symptoms in the future, it ended up being my exhaust cam position sensor.

Tommyfacekicker

Thanks for the update. How were u able to narrow it down to that sensor?

Teal2nnr

iTrader: (7)

Since i have a tubular manifold that sensor is prone to go due to heat. I do have a heat sheild over it, but i guess its just a matter of time. It was honestly just an educated guess. it was really odd though because it happened out of no where.