93HondaCivicDX

This is on my 1993 Honda Civic DX 1.5L SOHC 5 spd manual 184,000 miles. One morning I woke up, started my car, and immediately noticed it was idling rough. Not terribly rough, but not quite right. After driving it a bit, I pulled the wires one at a time to see what would happen. Pulling the 4th, going from left to right as standing at the front of the car, the wire arced but pulling it off had no effect on the engine. Pulling the 3rd had the exact same effect. Matter of fact I had both pulled and the car idled the same as it did with them both on. Pulling the 2nd almost shut the car off. Pulling the 1st almost shut the car off. So I assumed the issue was somewhere after the wire, as it appeared to be doing it's job. I also was told that when I hit the gas, white smoke emits out of the back. Not enough for me to see driving the car, but anyone behind me can see. I believe white smoke indicates a gas burning issue. Also, once this idle issue started my gas mileage dropped. I was getting about 36-37 mpg, but just filled up and am only getting 29mpg.

So I replaced the spark plugs and took note of each one. Plugs 1-3 had a white burn to each one but was relatively clean. Other than of course the white burn marking. The 4th had black on it & was dirtier than the others comparatively but more importantly I noticed there was liquid gas on the plug. After changing the plugs, 1-3 all seem to be working now. Pulling the wire from any of 1-3 almost shuts the car off. But still pulling the wire from the 4th and nothing happens to the idle.

I'm assuming that the 4th cylinder is not firing. What if anything can I do to fix this problem? I'm not a mechanic, but have fixed my cars in the past with the help of these forums. Any help would be most appreciated.

trustdestruction

I would start with a basic tune up of the ignition system.

Since you've already replaced the plugs, replace the distributor rotor and cap.

93HondaCivicDX

I did a complete tuneup less than 8000 miles ago. Plugs, wires, dist cap & rotor button, PCV valve, thermostat, oil change, gas filter, air filter, cleaned out the IACV. At that same time I even replaced the radiator, as it was cracked, both hoses, and of course bled the system out and replaced with new coolant.

Any other suggestions?

Townson

i've heard that sometimes the ignition has a hard time keeping spark to the engine at high speeds, which causes misfiring. i'm not sure if it's true or not though, so don't hold me to it. lol.

trustdestruction

I doubt it, Honda ignition systems are pretty decent.

schwazel

see if there is spark at the distributor cap. if not, try a new cap & rotor (you can always take it back). assuming that every thing is correctly installed, if cap, rotor, plugs and wires are new and functioning properly, and there is still no spark on cyl 4. then the ditributor has probably failed. i personally have only seen them not start at all when they go bad. but who knows?

93HondaCivicDX

I'm not having any issue with the ignition system. It starts just fine. My problem is the 4th cylinder is not firing. I know this because when I remove the wire from the distributor to the plug it arcs, but the car runs the exact same as if the wire was still in place. Whereas the other 3 now when any one of those wires are pulled, the car almost shuts off by bogging down. Also I noticed on the plug from the 4th cylinder, it had liquid gas on it when I pulled it, which also tells me the gas in that cylinder is not being fired. I need to know what would cause the 4th from not firing and how can I fix that?

trustdestruction

if the distributor failed then you wouldn't have spark on any cylinder.

OP: super clogged injector? injector not working? i'm stumped, lol.

93HondaCivicDX

There is a spark at the distributor. When I pull the 4th wire from the cap a spark arcs from it. Also there is a spark at the plug when I remove the wire from the plug. But again I don't think that spark is happening inside the cylinder since when I remove the 4th wire, the car idles exactly as if it were still on. Also when I pulled the plug there was gas still on the plug, which tells me it isn't firing in the cylinder or that gas would be burned off. The car starts fine. And quite honestly runs decent. Just the idle is off.

schwazel

the spark plugs firing the gas is part of the ignition system. look at the plugs see if the porcelain is cracked, shows signs of arching on the sides. also check compression.

schwazel

secondary ignition system, sorry.

93HondaCivicDX

If the injector is super clogged, is there a way I can unclog it? Obviously I'm stumped too. lol Just a thought, but do you think if that is the case, would adding some sea-foam to my gas have any actual affect on this? Or will I need to pull all of it apart and clean it? I have no idea how to do that, but would be willing to try if I could get my hands on the instructions to do so.

Thanks for the help so far.

93HondaCivicDX

I just changed the plugs last night, which is what brought the 3rd cylinder back into firing correctly. But the 4th is still not firing. So I highly doubt the plugs have any thing to do with this issue, unless of course the one out of 4 I bought was bad and I happened to put it in the cylinder that had the issue. Still highly doubt that. What else might I check to see if the secondary ignition system is not working properly?

Thanks for your help so far.

93HondaCivicDX

OK, I talked to a friend of mine who knows a little something about cars. He told me the white burnt residue on the plugs from 1, 2, & 3 are due to a gas burning issue. Possibly these 3 trying to make up for the 4th not firing correctly. As far as the 4th cylinder, he told me that more than likely the rings need to be replaced which is why there is oil on the plug. Does anyone else agree with this assessment? And if so, what's a ball park on cost for fixing this issue? I love this car. lol