I've got a '99 Accent 3 dr. 5sp with a 1.5L engine. There are only 142 000km on the car and up until recently it's run very well, I'm the second owner.

Running at highway speeds lately I've noticed that the engine starts to lag off and on very briefly but steadily at 80 to 110kmh. It's almost as though I'm letting my foot off the gas pedal very quickly. This has just started this past month.

Prior to that when the car is cold in the morning and I take off usually the shift to second or third the car will bog down completely to the point where it almost stalls. The more gas I give it during that moment the more it bogs, when I let off the pedal and slowly give it gas it will level itself out and run along no problem.

Fuel filter? Plugs?

 

sounds like your running rich. Now what do you mean its "almost as though I'm letting my foot off the gas pedal very quickly."? Is it the power drops as if you just let the gas pedel off? Are you still applying the gas pedal while this happens?

 

Hi Fintile

Exactly as you said it, I'll have my foot on the gas cruising along and the power drops as if I've let my foot off the pedal for a split second. Off, on, off, off, on, off, on.

Once I get onto city streets there is no noticable lag, hesitation or anything.

 

try to see if it happens at certain RPMs. Also did you happen to install any new injectors? New Fuel pump?

 

My car is a base model and does not have a tachometer installed in it. It happens at highway speeds. 80kmh/50mph or higher. I have not done anything to the car recently and have only done the necessities such as oil, filter and plug changes. I replace everything with OEM stuff.