Very sporadic issue question...

by "RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars" (rallydarkstrike)
Published 03/06/2017 at 12:44

Tags: Help
STARS: 1

Hi all! As many of you know, I’ve had very few issues with my 2009 Accent hatchback for the 4 years that I’ve owned it. There is, however, one very sporadic issue that has only happened like 3-4 times the entire time I have owned it that has me stumped that I’ve never bothered to solve. It came up again about a month ago and I’ve been thinking about it on and off ever since.

Misfire on start. There have been a few times now that I will start the car as I normally do and one of the cylinders will misfire on start and continue to do so. Shutting the engine off and restarting it a few times (usually 2-4, or in one case 6-7 times) usually solves the issue and then it starts running perfectly fine again and does so for months (or in at least one case, a year) until it pops up at random again. This is, as mentioned, an issue that happens very rarely for me. When it starts misfiring on start, aside from restarting the engine, I’ll also give it a TOUCH of gas (i.e. idle is 750rpm, I’ll rev it to like 1000-1200rpm) sometimes which seems to help solve the misfire sooner?

From experience, though my memory could be faulty, It seems to only happen on very cold mornings (although I seem to think it happened on a humid morning in the summer once too?). I also think the gas tank may have been low (less than a quarter tank) at least two of the times it has happened.

Talk me through what could be wrong here....I’M thinking condensation in the tank somehow? Is something working poorly until it warms up from the engine running and starts functioning fine again? Dying fuel injector? Maybe an ignition coil dying? OBDII scanner only throws the “Cylinder *insert cylinder here* misfire” code - which I seem to recall being cylinder 2 or cylinder 3 most times.

I’ve never had time to diagnose it as it’s always done it when I was in a hurry on my way to work, so once it starts working again I get on my way so I’m not late. And, of course, when I DO have time to actually look at it, it’s working fine again.

Thanks to the Oppo hive mind for any thoughts or ideas! :)

Replies (7)

"Party-vi" (party-vi)
03/06/2017 at 12:55, STARS: 1

Like mkbruin said, new plugs and coils should fix this. My friend has a 2011 Accent and that cleared up her issue.

"RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars" (rallydarkstrike)
03/06/2017 at 13:10, STARS: 0

Mine is the generation before hers then, but sounds like plugs and/or coils is the way to go!

Will have to pick myself up a torque wrench and try changing the plugs myself...is there any credibility to getting the more expensive iridium plugs?

"Party-vi" (party-vi)
03/06/2017 at 13:19, STARS: 0

Same generation. I don’t think you’ll need iridium plugs. Check on some of the Hyundai forums for the best plug suggestion, as I’ve forgotten what I put in hers.

"SidewaysOnDirt still misses Bowie" (sidewaysondirt)
03/06/2017 at 13:22, STARS: 0

Condensation getting on one of the spark plug contacts between the cable and plug? Would explain why it’s so sporadic, goes away when the engine’s warm, and only seems to happen when it’s humid or cold.

"RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars" (rallydarkstrike)
03/06/2017 at 13:32, STARS: 0

Ah, hers was one of the last of the MC generation then - the current-gen RB Accent model years started in 2011. :)

Prob don’t NEED the iridium plugs, but is there credence to the fact they work better (brighter, stronger spark = more thorough/easier combustion)? If so I would prob pick them up anyway....or would the stock coils in the Accent not be able to handle them?

"RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars" (rallydarkstrike)
03/06/2017 at 13:34, STARS: 0

Could be....I don’t see any obvious spots it could settle though, nor any breaks in the HT lead sheathing anywhere!

"Party-vi" (party-vi)
03/06/2017 at 13:55, STARS: 1

The coils aren’t going to present an issue. You could always go to the Hyundai dealer and ask what their OEM spark plug is as well.