Hi chevy experts, I have a 97 3.8L camaro RS manual trans, and I've been having acceleration problems. When i push the gas pedal more than just a little bit, the car starts to stumble and hesitate and it just won't accelerate normally. That is, if i do not depress the gas a lot, i can accelerate slowly and without any stumbling and hesitating all the way to highway speeds, and through all the gears. But if i give it any more gas than only about a quarter it starts stumbling; it will still accelerate but it is violent and not smooth and feels like it is hurting the engine. Air filter, fuel filter, cables and coils have been changed (though not the spark plugs, i think): that was all due to my mechanic hitting and missing while trying to fix the problem. So if anyone would have any idea what exactly might fix the problem so that i can tell the mechanic to just fix THAT and to not guess at the problem anymore himself, i would appreciate it very very much. Thank you Dan p.s. once i had poured 91 octane gas (i usually use 87 because that is what the manual recommends) and i felt like the problem went away and celebrated for about a day thinking that i have found the solution, but after a bit the problem came back, and i'm not sure whether it was because the next tank of 91 might have not been as good as the one that i thought fixed the problem, or perhaps there was no causal connection here at all between the 'better gas' and the problem going away (i guess, as they say, correlation doesn't necessarily imply causation)