Hey Scotty and everyone,
Occasionally (once in every 10 starts) the car has difficulty starting and it could be one of three outcomes:
1. It cranks for a little longer than normal - about 7-8 cranks - but starts
2. Starts after a couple cranks but the RPMs drop super low and stalls out within a couple seconds. Usually I can save it and keep it alive by pressing the gas pedal and revving it a little.
3. Cranks but doesn't start
I plan on cleaning the MAP sensor (no MAF in 2015 Sonatas I'm told) and I've had the battery checked at autozone and it's fine. My mechanic looked into it and couldn't replicate it enough to suggest any fixes other than to get fuel additives to clean the injectors.
All my internet research tells me that this should be happening all the time rather than once every few starts if it's one of the common causes. It's almost cyclical. Cold/warm starts don't make a difference, stalling out can happen on a warm start also. It's also a push button start.
Any ideas?
Thanks!
This model and year, with Theta II engines, has lots of engine related problems:
https://www.lemberglaw.com/2015-2016-hyundai-sonata-problems-complaints-lemon/
Well that's why Korean cars are not great long term, they are cheaply made, despite providing good value and they fall apart before 100 000 miles.
If the MAP and/or injector cleaner doesn’t fix it, I’d wait till the problem worsened and throws out a code.
It may not be wise to throw parts at it before you positively identify the culprit.
Throw a bottle of injector cleaner into half a tank of petrol, take it for a good long stretch on a highway (bonus if it's a manual, keep in in 4th gear so it'll rev above 3k). Cleaning the MAP sensor is a good idea too, it's usually somewhere near the throttle body if you're stuck looking for it
