Ideas on why car is not starting? Audio included

Car was running fine then went to start it after sitting for 10 hours and would not start. It is cold in Chicago area. Battery is 12.6 V and all lights and radio come on. Oil level and coolant is fine. There was/is an issue that happened once every few months when starting the car that there is no crank no start, I put foot on brake and nudge the shifter and it starts right up. Then I also have noticed sometimes that there is a gasoline smell after starting the car. Car eats up gas but it is a V6.

Hyundai Sonata 2006 v6 3.3 gls 100k miles

First video you can hear a hissing sound coming from the engine area.

Second video is from the next day after cleaning off battery terminals which had some corrosion.

2nd video

Your car cranks but does not start because the engine is flooded since you smell gas when trying to start it. You have to wait for gas to evaporate then try again. I would remove spark plugs to let them air dry and check them for wear or replace them if they are old.Battery seems fine.When starting a flooded engine,leave your foot on the gas pedal and crank the engine but do not crank to many times because you could fry the starter.

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Thanks will try that.

No go. Spark plugs seemed somewhat clean (will post pic later). Though I could not look at the back 3 because the plenium/manifold has to be removed. Pressed gas pedal while starting. Also tried it with fuel pump relay removed.

Also would any info on a obd2 scanner be of value? There were no codes but it has a live reading section.

just a thought. seen a video for your car where there was an oil leak in the front dripping on the o2sensor which caused the number 19 fuse to blow. and the vehicle would crank but would not start

Thanks. Seen that and 02 sensor is dry and fuses are good.

Should the fuel pump make a noise when turning the ignition in the on position on a Sonata? I’ve read some cars fuel pump will only make a noise/buzz when engine is started. I hear nothing coming from the fuel pump with ignition on.

yes, you should hear a noise from the fuel pump kicking on for a few seconds. turn your key forward but do not start it and listen. sometimes it is hard to hear. stand near the gas tank and have someone turn the key for you. if you do not hear it, I would start by checking the fuses and changing the fuel pump relay. look to see if you see another relay that is the same as the fuel pump relay and temporally switch it to see if it starts.

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I have a 2004 V6 Hyundai and have experienced similar problems.
My solutions were:

  1. Very occasional non-start - Jiggled (technical term) the gear selector a couple of times and the problem was solved.

2 Gas smell - On the driver side, there’s a rubber fuel line running up to a connection on top of the engine between the cylinder banks, which I suspect is a fuel overflow line. Where the rubber connects I noticed cracking of the rubber tubing, probably caused by age and constant engine flex. Temporary solution was to cut off the 1/2 inch with cracks and smell was gone BUT because I prefer not to set the car on fire, correctly making the repair by replacing the line is a high priory.
. between the there’s

Sounds like no fuel pressure in the first video. The second video sounds like no compression as if the valve timing has slipped.

Hissing sound maybe exhaust pressure leaking out from a clogged cat?

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Heard nothing at gas cap or at the fuel pump itself, though I had no one around to help, but it was quiet out and left my phone recording on open gas cap and on top of fuel pump, heard nothing but me turning the ignition on. Pump fuse is good. Swapped horn relay with pump relay, horn works with fuel pump relay.

I bought a set of 6 relay bypass switches with amp loops and a DC clamp meter but none of the switches fit my relay outlet. Is that a waste or a good option to go with?

I was thinking if I turned on the relay bypass switch that would allow me to start the car enough to drive it until the fuel in the line after the fuel pump burns up? How far could you drive it? That would burn up the rest of the fuel so there would be no more fuel pressure, so when I remove the fuel pump pressure line, fuel will not come spraying out? There is no pressure valve in the engine bay.

I had the same issue with the starting and jiggling the shifter.

Maybe that was the fuel pressure line that is a metal part with 4 bolts connecting to the top area of engine around the fuel injectors then it turns into a rubber hose going into the back area of the engine? But then again if it was the pressure line, I would think it would not run if cutting the hose.

if you are not hearing the fuel pump turn on for a few seconds when you turn the key but don’t start it. and the fuses and relay are good. then it is either the wires going to the pump might have a cut or fray in it, or the fuel pump is bad. most likely it is the pump.

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No, the metal line is the injector rail which brings high pressure gas to your injectors.

This is a low pressure black rubber fuel line running from the center of the engine V down to somewhere on the back (other end from the belts) of the engine. Even a tiny amount of gas leaking on top of a hot engine makes an incredible stink when it’s sucked into your ventilation ducts BUT any gas smell is a priority to be addressed.

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Thanks. I’ll look at that.

Ok thanks. Since the car does not have a pressure release valve by the engine and I can not start the car to empty the fuel line, how much gas will release from the pressure hose when disconnecting it from fuel pump?

Is it a strong pressure that will spray everywhere?

Does the gas release under pressure from the fuel pump connector when you start unclipping the connector or when you pull the hose off?

I was thinking to just pinch the hose and put the hose end in a gallon ziplock to drain the gas .

You can disconnect the fuel hose and it won’t be under pressure. Only a minimal amount will start coming out. If it doesn’t have a fuel return line then there should be a bleeder valve at the other end of the injector rail. You can open that like you let air out of tires.

But you seem to be going at this the hard way. If there is no fuel pump sound then there is no fuel pressure. It will run for a couple of seconds tops with no fuel pump. It’s not like the old days of a carburetor and a bowl. You also shared an audio recording of an engine cranking that sounds like it has no compression. Maybe you have much bigger problems than fuel pressure.

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Do a compression test

It started up. I was trying to disconnect the power harness on the fuel pump to check it over, was not sure how the tab opens, never disconnected it, but I was moving that around and I also gave a few wallops under the tank. Then I put my phone on top of the fuel pump to record and put the bypass relay in the fuel pump relay spot (one of the bypass relays in the kit ended up being correct but it does not seat fully in the relay slot) and I turned that on (no key in ignition) and then heard the pump working on the video. Then the car started after a few tries after the engine was putt putt putting. I’m still not comfortable driving it.

Is a compression test still a priority?