My son just purchased a 2000 Hyundai Sonata Automatic 4 cylinder 2.4 L that has 39,750 miles on it. At first his test drove it with no problems before buying it. Now after driving it for a little while (week or so) he noticed at times it hesitates somewhat from a stop when he presses the pedal. I checked over the car fluids, etc. and everything seemed fine at least eye view. I drove it a few times myself with no problems. At that point I thought maybe my son has the issue. Anyway, I took it out again and this time I noticed when I pressed the pedal it hesitated to go and almost felt like no gas was getting to engine. I let back on the pedal and pressed it slowly again and it finally went. I have read where this car has sensors for the auto Trans so I am not sure if one of those were bad would it cause this to happen. I would hate to think it is the fuel pump, but I kind of vote that out since it doesn't happen often. I am going to try change the fuel filter, plugs, cap, and rotor (if there is one) and add fuel injector cleaner to see if it was just bad gas. He added 10 gallons since having the car so I am not ruling out bad gas. Another thing I noticed that it does go up to around 3,000 rpm's at times before going either 2 and 3 or 3 and 4. I am not familiar with Hyundai having never worked on these cars, but almost all other brands.
At this point I am really puzzled on this.
Any help or suggestions would be greatly appreciated.

 

Do you have any check engine light ?

ps: i have the same problem, but i guess it is related to my actual fuel problem with my 99' sonata (check my post for details)

In my case, i have allready changed my fuel tank, fuel lines, fuel filter, but didn"t change my fuel pump, now i regret it,

This car is a lemon, and i hope your son will have less problems than me...

 

I'm replying to the question about the 2000 hesitation from a stop, I just bought a 2008 hyundai sonata with the 2.4 DOHC 16v basically same motor I believe. I had the exact problem with mine, it went down the same as well, didn't notice till a few days later. Mine has 62k miles so I thought i'd check the spark plugs. Sure enough they were all worn pretty good but cylinder #4 was especially worn... I put a set of Bosch Platinum X4 plugs in it and it runs like a champ. My car DOES NOT have plug wires so im not sure if is will either. Mine simply has 4 individual ignition coils that connects directly to each plug so i doubt the problem is with one of them. I suggest checking the plugs and if they need replaced that's more then likely the problem in my opinion. By the way, my car has an aluminum head so be sure to use anti-seaze on the threads of the plugs when installing if his does as well, really should use it regardless of what it's made of but aluminum heads are more prone to stripping out... Home this info is helpful and if you could let me know if that was the problem and good luck

 

No, it's not. It's a totally different engine. The 2.4L in the 2000 Sonata is the Hyundai/Mitsu "Sirius" engine. The 2.4L in the 2008 Sonata is the Hyundai "Theta" engine.