Ozolins

Hi, I bought a 94 civic VX this summer and I've been lurking on these forums collecting tips and ideas. I've been slowly tuning this car up and addressing a hesitation/inconsistent idle. I have read many tips on various forums about where to check and I'm only partway through the list. The car is all stock except for a cobbed on muffler that I'm about to replace. I recently replaced the plugs and wires with the recommended ones, as well as the cap/rotor, air filter. Timing belt, water pump and associated parts were just replaced, and valve timing that was off by a tooth was set right. The melted catalytic converter was just replaced, too.

The idle is not usually hunting or surging, though sometimes it is a little. Mostly it's just inconsistent -- in the 400 to 1000 range when warm or 1200 to 1500 when cold. The Hesitation is when I am cruising with little gas, there is a subtle but quite noticeable hesitation when you begin to accelerate. As in give it some more has and it sputters, then accelerates. Sometimes when going harder, too, there will be a stumbling and it almost seems like moving the gas pedal will change it -- not jus giving more gas but going back and forth a little. It's drivable, but annoying to me and I'm getting milage around 25 to 35. only a little better on highway.

If any of this points to something in particular, I'm happy to get suggestions even though I haven't exhausted the list of things to check.
One thing I have noticed while driving, however is that if I put the clutch in when I am coasting toward a stop and the engine goes to idle, it will actually surge quite a bit, then right when I come to a complete stop, it settles to an even idle--where ever that will be. As thought some condition in the engine management is changing when I actually stop. Does this sound normal, or point to any particular fault?

Thanks in advance. I've enjoyed reading all of your helpful hints so far.

EGRhatch

WELCOME,
Well as I don't have a solution for you, I have a 93 vx with ~220K on the clock and it does the same thing.

right around 2K-2300 rpm there is a surge like what you described and i do the same thing, on/off/on the throttle.

I thought it was an ignition issue so I swapped spark plugs/wires and adjusted valves as well.

a friend of mine that is a tech at BMW said there could be a bad injector and that could be causing it to stutter a bit. So I will be replacing injectors next, but not until i get some other things going so i don't have any down time. (this is my DD)

and I'm averaging between 39-45 mpg (been getting ~418-425 miles per tank)