Startup problems

JRINER0514

MEMBER
2013 HYUNDAI SONATA
2.0L
4 CYL
2WD
AUTOMATIC
123,000 MILES

My car has recently been having issues where it fails to start after I turn the ignition. I usually have to wait until I hear it "catch" or begin to turn over, then press my gas pedal, at that same moment, in order for it to start completely.

Once running, there are no issues. I recently had my battery, alternator and starter checked via diagnostic tests, and everything came up still good.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,740 POSTS

Welcome to 2CarPros.

Based on your description, the first thing I suspect is a fuel pressure issue. Interestingly, I suspect it to be too high.

When you depress the throttle to start it, that shuts down fuel injections or at least limits the amount of fuel entering the engine. Have you ever noticed any black smoke from the exhaust?

Now, the first thing I suggest is to check the fuel pressure. If it is too high, suspect a faulty fuel pressure regulator.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Next, I need to know if this only happens when the engine is warm. If it does, then I need you to read through this link. It deals with the crankshaft position sensor. When they start going bad, they are adversely affected by heat which can cause failure of ignition spark. If that is the case, excessive fuel can build up in the cylinders due to no spark and require you to press the accelerator to eliminate flooding.

These links explain the sensor's function, symptoms of a bad one, and in general how one is replaced.

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Let me know if the symptoms listed in the link mirrors what you experience.

Let me know what you find or if you have other questions. Also, I have the specific directions for your vehicle for part replacement once we determine what is happening.

Take care,
Joe