97 Malibu V6 3.1L Fuel Milage and Acceleration Become Poor

Hello,

My 97 Malibu recently shows poor fuel mileage and weak acceleration on local. Whenever it starts to run on an up ramp or accelerates from low speed, it shows some difficulty and was not very responsive.

After I replaced a new air filter, it seems to have improved the acceleration on sevreral road test.

Are there any other sources that could result in poor fuel efficiency and acceleration? Any suggestions to further improve it?

Thanks a lot!

While I am giving gas on the pedal, I hear a slight noise which sounds like "Ji Ji Ji Ji...", whose volume is proportional to how much I decompress the gas pedal.

If no gas is applied, then the noise is gone. The noise is from the front part of the vehicle. Is it from the engine, the alternator, or the belt? Will it reduce the fuel efficiency?

Please help diagnose, thank you!

Check your fuel pressure, and do an ohm test of your injectors.

Fuel pressure test on youtube 'fuel pressure test'. Might be able to rent one from Advance / Zone. Ohm test video sticky in forums.corvetteforum.com c4technical / performance . top of column, right under my headlight repair sticky.

Post back results.

Check your fuel pressure, and do an ohm test of your injectors.

Fuel pressure test on youtube 'fuel pressure test'. Might be able to rent one from Advance / Zone. Ohm test video sticky in forums.corvetteforum.com c4technical / performance . top of column, right under my headlight repair sticky.

Post back results.

Hello cbec1999:

I havn't got a chance to check the fuel pressure and injectors yet, but the problem is gone now.

I replaced the air filter for $12 and found out the old one wasn't in good condition which I had assumed. Although each time when I change the oil I would ask the mechanics to check if the air filter needs to be replaced, all the answers that I got was the air filter was all right. However it wasn't at all. It's just because the screws of the filter cap are locked by the rust and all the mechanics simply didn't want to bother to unscrew them for the free check. That is all the reason behind it!

One day after replacing the air filter myself, the engine of my 97 Malibu V6/3.1L is breathing very smoothly and solidly. The acceleration is confirmed to be great and powerful again after a few road tests. I can feel it is young again.

The fuel mileage is improved back to normal as well.

I will also check the fuel injectors whenever I got a chance to see if any cleaning is required.

Thanks a lot for your help, cheers!