95 power / transmission issues

[jmark7]

I have recently purchased a 95 LX with 80K and dual exhausts, nice car.
I noticed that the car had slight hesitations so the first thing that I did was replaced the original plugs which solved the problem.
Most of the time the car drives like a rocket. Smooth sporty transmission shifting, easy start. Occasionally, it seems like the engine revs to high and it takes to long for the gears to shift resulting in a much louder engine noise and sluggish acceleration. This has very little to do with the engine temperature. It could happen any time.
Also my average city gas mileage is under 15mpg.

Any advice?

Thanks.

[ModMech]

Check the ATF level, check it when HOT on LEVEL ground with the engine running and the transmisison in PARK. Top off as needed (I'd bet it's low), you can add EXACTLY 1/2 PINT more than "full" and that should cure it.

You should REALLY have the ATF changed anyway, replace it with ONLY Mercon V type fluid (~13 qts). Do not change the ATF if it looks or smalls really bad, you will kill the trans. After the ATF is changed, disconnect your battery for a few minutes.

You poor fuel economy can be caused by:
-low tire pressure (35 PSI mn.)
-being out of alignment
-brake(s) dragging
-dirty/bad oxygen sensors
-oxygenated fuel (you should still get at LEAST 22 MPG average even with this junk).

[jmark7]

The transmission level and color are fine. However, I believe that is has never been changed.
Thank you for your good advice.