My car wants to stall when accelerating-Hyundai Elantra 2008

stalling
gasoline
hyundai
elantra
shifters

#1

I have a 2008 Hyndai Elantra with an automatic transmission. Since the first week I have had my car when the fuel is low (under a half of tank) the car tends to hesitate like it wants to stall, or momentarily shifts into a higher gear than it needs to be for the situation; the rmp’s get very low. As the tank drops further below half full, the problem gets progressively worse, especially while trying to accelerate hard; i.e. entering the highway, starting from a red light, etc (times requiring a lower gear). I have brought my car to the dealer for service three times also asking them about this problem. Each time they can not replicate the problem which seems ridiculous since it is difficult to not have the problem when the tank is low.

The day I purchased my car I was speaking with another Elantra customer who was waiting for her car in the service department. She had just purchased her vehicle as well and already had to bring it in for a fuel pump recall. I believe the recall states that the fuel pump fails and causes the car to stall, sounds very similar to what my car wants to do. I have asked about this recall on my vehicle and have been told that it does not affect my car.

Does anyone have an idea what may be causing the problem, or is anyone having the problem as well?


#2

You’re describing the symtoms of a weak fuel pump.

The reason the fuel level in the gas tank has an effect is because when the tank is full the higher level of gas provides what is called head pressure. This head pressure then assists the weak fuel pump in delivering the proper pressure and volume of fuel to the injectors. As the fuel level in the gas tank decreases the head pressure also decreases. The head pressure then falls to a point where it no longer assists the weak fuel pump and the fuel pressure and volume falls off to where the engine will lack power, stumble, and stall.

The only way to check if it’s a weak fuel pump is perform a fuel pressure test when the gas tank is below half full to see if the fuel pressure is within specs.

It’s not unheard of to purchase a new vehicle with a faulty component, such as a defective fuel pump.

Tester