2001 Hyundai Sonata MYSTERY PROBLEM

For about 2 years my Sonata has been acting funny, especially when the weather is cold or I’m low on gas. It’s very jerky when accelerating, like the gas pedal just isn’t connecting with the engine, and the car won’t go right away. Sometimes while I’m driving I can feel it shifting gears very hard and I can see the needle on the RPMs jumping up or down very suddenly.

The car has been in and out of different mechanic’s shops, including the dealership and no one can find anything wrong with it.

I’ve only had one check engine light last spring and it coded for the air filter, which had been recently replaced. We’ve also changed the spark plugs, used a fuel injector cleaner, checked the fuel injector, nothing seems to fix the problem and the car still runs like crap most of the time.

I don’t know what to do and I can’t keep taking it into shops when these mechanics keep telling me they can’t find anything wrong with the car. Any suggestions?

How many miles on this Sonota? How did they check all the fuel injectors? Just adding a bottle of fuel injector cleaner to your gas tank probably didn’t help much. I’d stay focused on the fuel injectors, but that’s just a guess.

New spark plug wires wouldn’t hurt either.

Try replacing the inline filter (just after the gas tank). You should not ever run a car below a quarter tank. Everything that can go wrong with your fuel, from rust to impurities lives at the bottom of your tank. Consider the tank empty at half-full.