View Full Version : Bad gas mileage and a little hesitation!

06-20-2004, 11:37 PM
I need help! I'm tired of asking mechanics to diagnose this problem, get charged for the fix, and then have the problem come right back! Does anyone know why my 95 Z-28 with ~70K miles would be losing 100+ miles to the tank and acting sluggish? I noticed the problem a few weeks after I ran it dry of gas about 18 months ago. I know, I know...bad! Bad! Bad! No excuses...

Here's what I've done: new fuel filter (twice), flushed/cleaned the fuel injectors ("professional" did it and I noticed improvement for a few weeks), new high performance plugs (ran very bad after awhile)...but then replaced with plain GM plugs (ran better for a while), new spark plug wires.

There's been little change in my driving habits (city vs hwy) since the mileage has taken a dive. As for the hesitation, if I punch it (no matter what gear) my stick shift nearly shakes my hand to death because of the engine vibration. It acts like I'm going too slow (giving too much gas) for the gear I'm in. But it does this in every gear. There is some improvement in acceleration once I'm over 3K RPM, but I don't want to drive my car like that from every stop light!

I know this is a lot to take in at once, but I'm out of ideas to fix the problem and I can't accept that it is just wear and tear. I want my car back the way it was before I ran it dry! Can anyone throw any suggestions my way? Thanks for any advice you can provide!!!!

06-21-2004, 08:51 AM
First thought at ~70k is o2 sensors, if not then maybe bad ignition coils.

06-29-2004, 09:41 PM
First thought at ~70k is o2 sensors, if not then maybe bad ignition coils.

Thanks for the reply. I've got a buddy at work that has owned 3 camaros (2x'94s and 1x'94) and he thinks my problem lies with a clogged (muffler/cat. conv.). He says the honeycomb filler breaks down fairly easily and can be causing back pressure to the engine. Your thoughts?

06-29-2004, 11:06 PM
Cats don't go bad by themselves. Not to say the cat can't be clogged, but then something else is wrong and killed the cat in the process. If this was the case, you'd notice a general lack of power across the board. No shakiness or stumbling, but just crappy power. Sound would be affected as well. If the car is running reall rich for long time, then the cat could have been damaged.

07-02-2004, 01:44 AM
Check your opti-spark. Someone should shoot the engineer who came up with that great invention (opti-spark)