Ok, I have a 91 Civic hatch with the D15B2/four speed manual combo. A few weeks ago, it started running really rough and was belching moisture from the exhaust. I took the bus for a week or so, and then tried driving the car around - I found I could limp it around town as long as I heel-and-toed the brake and gas at stoplights to keep the engine from stalling. It needs a little prod of the throttle at startup to catch, but it will every time. Hot, it's more of a struggle to start up, but it can be done.

I started trouble shooting, and I found out that the #4 cylinder isn't firing. I replaced the cap, rotor, and wires, but it didn't help a lick. Tried replacing the plugs (NGKs), no luck. Checked the spark for that cylinder against the valve cover, and it's sparking away. There's absolutely not one iota of difference when the #4 wire is disconnected. There's no oil in the coolant or vice versa, and the moisture doesn't seem to be present anymore.

The car did have a problem burning oil (bad valve guide seals) but it hasn't been a problem at all - just add a quart every 75-100 miles depending on driving conditions and don't worry about it. More frequent plug changes, sure, but it beat replacing the D15 with another one from Nippon Motors - I'm trying to save for a ZC swap.

I thought that maybe the air filter was clogged (it wasn't , but I checked it without the filter box attached and it didn't help), or that the cat was maybe caked with oil - it wasn't, but I ran it without the exhaust attached (cat-back - the exhaust manifold up to the cat was still attached) and no improvement. Oil consumption seems pretty much unchanged, but my mileage has gone down a lot and there's the smell of unburnt fuel, especially at startup.

Interestingly enough, the car has gotten better the more I drive it - the idle has smoothed out somewhat in the last few days ands startups are easier, and it doesn't want to die at lights, but there's still barely enough power to drive with (between the way it runs and sounds, and the lack of power, I can close my eyes and pretend I'm driving my old Beetle! NOT good!).

I'm trying to avoid paying for a diagnostic check, and thus I'm putting this out there in the hopes that someone else has encountered the problem and knows what to do. I'd try to run the on-board diagnostic, but aside from once on the highway (it'll actually do 60-65 on a flat run fairly smoothly) the 'check engine' light hasn't come on! Great engine monitoring on this model, Honda, you've really outdone yourself...runs on three cylinders, but according to the computer, everything's a-ok!

If anyone would like to help a poor mo-fo out, I'd be much obliged.

Thanks,
M13