ColtHard

I, well, my girlfriend has a 94 civic EX with the d16z6 in it. Its an automatic with an intake, gutted cat, and a solder in ECU mod chip. I have driven a 93 del sol with the d15 in it that was virtually stock and i have to say that car was phenominally faster than this d16z6 civic, which, from my understanding should be significantly faster. I've put every expendable tune up item that i know of on it and to me, this car should not be as slow as it is. It practically goes 0-60 in like two weeks(but really, just roughly using a wristwatch its more like 13 seconds). I can't even comfortably pull out in traffic in a 55mph zone. I've checked the time and set it at 16dBTC with the service connector jumped as well. For an engine that is supposed to have 125hp stock, it doesnt feel like it has even half of that. There really isnt any RPM range in which it feels like it has more power. In the upper RPM ranges the motor definitely wastes a little fuel and spits out a small amount of black smoke, but from my understanding is not uncommon on a weak factory ignition. The check engine light is not on so there are no trouble codes. Every modification ive made to this car have had very little to no effect on its performance. I'm not looking to make a super dooper drag car or anything, but dangit, if i want to pass someone, id like to at least be able to have the power to get around a car safely. Is there anything that is common to fail on these cars that can cause a significant HP drop? Is there anything within a reasonable price range that i can do to boost my overall performance? The car has a little over 200,000 miles on it as well, but does not burn any oil. Also, i put some powdercoat 15 aluminum wheels on the car. when stood next the original tires and wheels they were actually the exact same height due to the lower profile tire and being aluminum they also weigh less than the original steel wheels, so i wouldnt think that could have had any effect on my performance. I drive a hopped up 84 vette so im used to working on older stuff and im also used to having some get up and go when i want it so every time i drive this car its very disappointing. Anything you guys can enlighten me on would be greatly appreciated.

sxysweed

FYI, there's really no 'Performance Chips' for the D motors.

Milage difference, compression test, leakdown test?
Could be the Z6 is simply older and more worn.