2011 Hyundai Genesis 4.6L - Starting/Driving issues.

[jazzie366]

Greetings lads. I had an odd occurrence today. I have the aforementioned Genesis above and it gave me it's first mystery today. I started the vehicle and drove it to the store like normal, nothing was out of the ordinary, lots of power and fun. Then when I got back in after maybe ~20 minutes of sitting, it wouldn't start at all. All dash lights came on like normal, just cranked but no start whatsoever. I tried this 3 times and thought I was stuck. However, I am a technician so I listened to see if I heard the fuel pump which I did. I depressed the gas just a little bit and it sputtered to life and idled high. It also went into gear quite harshly as if it was in fail-safe mode. When I went to drive down the road, it had no power whatsoever, like it was lacking fuel. However, once I brought it to my shop I scanned it an no DTCs/codes whatsoever stored in the computer, all emissions monitors still passing. Puzzled, I looked under the hood and found.... nothing amiss. So I decided to drive it and see if anything had changed, and the car was completely back to normal after turning it on and off one time. Has not done it since but I do not want to drive it if this is going to be an issue. I suspect a fueling issue as vehicles that have low fuel pressure exhibit this issue when they do not want to start and lose power. The reason for my thinking it's fuel pressure is because when a vehicle has low/no fuel pressure, by pressing the accelerator pedal, you are causing the injector pulse width to be wider which allows more fuel to dribble out. This will cause it to sputter/run poorly, in this case it ran fine other than a high idle and no power.

Any insight is appreciated, let me know what you all think. I will be testing the fuel pressure ASAP to make sure it's within specification. If any of you would like me to post the testing procedure, I will.

 

[chrev]

There is a emission valve solenoid on top of the engine that allows the fuel vapor back into the head. It can fail and essentially fuel lock the cylinders and it will have trouble starting. I had the same problem. If you pull it off and you can't blow through it then its bad.

 

[PRINCE KEN]

Greetings lads. I had an odd occurrence today. I have the aforementioned Genesis above and it gave me it's first mystery today. I started the vehicle and drove it to the store like normal, nothing was out of the ordinary, lots of power and fun. Then when I got back in after maybe ~20 minutes of sitting, it wouldn't start at all. All dash lights came on like normal, just cranked but no start whatsoever. I tried this 3 times and thought I was stuck. However, I am a technician so I listened to see if I heard the fuel pump which I did. I depressed the gas just a little bit and it sputtered to life and idled high. It also went into gear quite harshly as if it was in fail-safe mode. When I went to drive down the road, it had no power whatsoever, like it was lacking fuel. However, once I brought it to my shop I scanned it an no DTCs/codes whatsoever stored in the computer, all emissions monitors still passing. Puzzled, I looked under the hood and found.... nothing amiss. So I decided to drive it and see if anything had changed, and the car was completely back to normal after turning it on and off one time. Has not done it since but I do not want to drive it if this is going to be an issue. I suspect a fueling issue as vehicles that have low fuel pressure exhibit this issue when they do not want to start and lose power. The reason for my thinking it's fuel pressure is because when a vehicle has low/no fuel pressure, by pressing the accelerator pedal, you are causing the injector pulse width to be wider which allows more fuel to dribble out. This will cause it to sputter/run poorly, in this case it ran fine other than a high idle and no power.

Any insight is appreciated, let me know what you all think. I will be testing the fuel pressure ASAP to make sure it's within specification. If any of you would like me to post the testing procedure, I will.

Maybe your lovely 4.6 is just mad at you because you haven't been taking care of her properly. Just kidding mate. Due to the age of your vehicle you may want to consider changing your "Purge Valve Selonoid" in your engine bay. It's should be very easy for you if you are technically inclined It's part of the emissions system that controls the stability of your 4.6 engine