2012 Hyundai Elantra Starting issues


#1

My wife has a 2012 Hyundai Elantra limited with 59,000 miles.The last 4 months we have been experiencing intermittent starting issues. Since the car is a push button, it will crank for about 15 seconds before it actually starts, without her actually having to keep the key in the ignition turned. These long starts may happen about twice a week. In addition to long starts we experience, bucking when you initially start the engine and the car is in park the car seems to fluctuate in RPM’S quite a bit, however, once the car is in drive and we get to more than 10 miles an hour there is no bucking and the car will drive as normal until we reach our destination,even when at a stop light. The bucking seems to happen at least once a day.

The problem only seems to occur when the car is initially started. We took the car three mechanics, one suggested we try to use high octane gas with a fuel injector cleaner while driving at 60 miles per hour. We tried that several times to no avail. The second mechanic simply asked if the check engine light was on, and we said no. He concluded that my guess was as good as his. Finally, we took the car to the dealership. They also didn’t see any check engine light warnings and concluded that they couldn’t help us.

Is there anything that I can do, or do we have to wait for it to get worse before we solve the problem.
Any help will be greatly appreciated.


#2

Someone on carcomplaints.com is complaining of a similar issue with his 2012 Elantra. Please read this:

My 2012 Hyundai Elantra is a good car overall, but 1 year after purchase, I also started to have the car not starting up thing. It started with minor no starts, which would start on the 2nd or 3rd try. Then as months went by, it started to get worse, sometimes requiring a 5 minute wait or more. The first time I took to the dealer, they couldn’t find the issue. The second time, they knew exactly what it was. I’m guessing I wasn’t the only one complaining. They changed the ‘RANGE SWITCH’ on the transmission, and it’s been fine ever since. Has been 2 years now and still good. It was covered under the standard warranty too. Hyundai stand by their products.


#3

I think the complaint you cited is describing a problem different from OP’s car

I would expect a faulty transmission range switch to prevent the starter from even engaging in park and neutral

And OP has no problem with that. The engine apparently cranks over normally

Based on the symptoms, it sounds like it could be a fuel problem


#4

Abnormally long cranking periods have several potential sources, but from the comments we get here on the complaint, the problem is often the fuel pump. There’s a check valve inside the fuel pump that is supposed to prevent gasoline from draining out of the fuel rail and back into the tank when the engine is turned off. That depressurizes the fuel rail, and so when you start the engine the next time the pump has to pressurize the fuel rail first, before it can start the engine.

Ask your shop to perform fuel pressure hold-time test. They’ll hook up a fuel pressure gauge to the fuel rail, start the engine and let it run a minute or two until the rail pressure stabilizes, then they’ll turn the engine off and monitor the rail pressure over a 2-4 hour timeframe. The fuel rail is supposed to act sort of like a balloon, pump it up and it stays pumped up at full pressure, 40 psi or whatever the spec is. If there’s a leak back into the tank the fuel pressure will gradually drop to zero.

On some cars – not sure if it applies to yours – as a test you can turn the key to on several times. On, but don’t start the engine, then back to off. Repeat. Each time it will cause the pump to run a little while. If that helps, you know the fuel rail is depressurizing. There’s other paths for a leak to occur, but it seems to usually be the fuel pump check valve. That test wouldn’t work on my Corolla b/c the fuel pump doesn’t run just b/c you turn the key to on.


#5

Have you been keeping up with the maintenance?
When was the last time the spark plugs were changed?
Do you have or have you had a Check Engine Light (CEL)? Was it solved? How?

The symptoms you describe are often caused by simple neglected maintenance.
Other possibilities mostly involve fuel delivery and metering.
Fuel delivery involves the fuel pump. This can be tested.
Metering requires proper readings from a variety of sensors, including the temp sensor, the mass airflow (MAF) sensor, the manifold absolute pressure (MAP) sensor for those cars that have them, the oxygen sensor(s), the throttle position sensor, the crank position sensor, and perhaps one or two others that I’ve ignored.

Most of these will trip the CEL if they’re bad, but not usually the fuel pump. Problem is, the ECU won’t generally trip a light for most of these during the start cycle… or you’d constantly have a CEL. And it ignores the oxygen sensor(s) when the engine is cold to allow rich operation until the engine warms up.
Oh, and it won’t trip a light for the temp sensor because there’s no monitoring function for its operation. It’s an unmonitored input.

The first thing I’d recommend is new sparkplugs. And if that didn’t do it I’d test the temp sensor output and the fuel pump pressure.

I hope this helps.


#6

The lack of oil changes or air filter replacement will cause long crank time? What maintenance neglect results in long crank time?

The engine operating temperature is monitored, even years before OBDII was implemented. When you see the fault P0128, “coolant temperature below regulating temperature”, don’t you find this as a prompt that the thermostat has failed?

If the vehicle is left at the repair facility long enough to replicate the problem it can be diagnosed.


#7

Sparkplugs, you… oh, never mind.

Do you have any suggestions for the OP or just criticisms of my post?
Did you post here to help or to criticize?

Never mind, I know the answer to that question too.


#8

Thank you all. I will ask my shop to preform a fuel pressure hold time test on the vehicle to see if there are any leaks in the system.
I looked up symptoms for a faulty range switch in the transmission, and my car doesn’t appear to have many of the associated problems.

We preform regular maintenance on the car, and a check engine sign has never appeared. Also, the car only has 59,000 miles so we never changed the sparked plugs because they are typically changed after 100,000 miles. Also, wouldn’t the spark plugs show mal effects during driving of the car, such as: slow acceleration, uneven acceleration, and bucking? None of those things happen when I drive. It only seems to happen during starts.

Also, I was wondering if the problem was temperature induced, would the ambient temperature, hot or cold, cause the problems to magnify.

I’m trying to think for some of pattern to this, but as of now, I have found none. In addition, to testing the fuel system is there a sensor that will cause these intermittent effects. It seems very interesting to me that the car drives fine but only has problems during starts.

Thank you all so much for your thoughts and suggestions!


#9

It’s consistent with a slow leak in the pressurized part of the fuel system. Consider my own bicycle tire for example. I pump it up before each ride, and during the ride it performs flawlessly. By the time of the next ride a few days later, it is nearly flat. Why? B/c it has a slow leak, the effects of which don’t show up until enough air has leaked out; i.e. the next day.


#10

Gotcha, makes sense! I’ll definitely get it tested.


#11

I am still trying to identify a pattern, so correct me if I am wrong. If there is a slow leak, I should probably notice the long starts after not using the car for a while. I also probably won’t notice the long starts after a quick run to the grocery store.

I reached that conclusion, because I am assuming that there will be more air gaps in the fuel system after the car hasn’t been used.


#12

Perhaps, but when trying to solve a problem it’s wise to consider and test for all possibilities.
One “quick test” you can run to determine if your fuel system is losing pressure is to, when you go out in the morning, turn the key to ON without turning it to START three or four times for three or four seconds each, only then turning it to START. This will allow the pump to repressurize the system, and if pressure loss is the problem it should start right up.

Air cannot enter a deenergized fuel system unless there’s a leaky injector. When deenergized, injectors close, and the injectors act like a pipette (or a straw in a glass of soda when you put your finger over the top and lift it from the glass and the straw lifts the soda up with it), preventing entry of air into the system.


#13

Yes, that’s generally correct, but for the second part it depends on how “slow” the leak is. They’ll be some amount of time after turning off the engine after which it will take longer cranking before it starts. So you could try a variety of waiting times to determine what that time interval is for your car.