DOHC ZC 4th Gen

Basic run-down:
I just recently bought my first 91 Civic Wagon FWD 5 speed that's been sitting in a garage for about 4 years since 2010. I bought it for 500 with an engine problem. I thought it had low compression because of the misfires(cylinder 1 and 4). I tested it and it was good all around. One of the injector wires to injector cylinder 4 was cut off so I had to rewire it. Cylinder 4 started working again but cylinder 1 is still misfiring.

Things I've already done:
-Checked for compression, 130psi across(pretty low..)
-Checked for spark, all spark
-Checked for fuel, all injectors are clicking
-Checked for loose or cut wires to dizzy and other places and all seem to be fine besides the one I had just rewired
-Checked for leaks, no leaks
-Checked for burns, little white smoke comes out but I think that is due to the fact that it has been sitting for a long time

Now what I've noticed:
-Spark plug on cylinder 1 has carbon build-up, my guess would either be: 1)bad piston rings 2)bad valve stem seals 3)or a leak somewhere

Knowing that it can be multiple problems, I'm going to start replacing the valve stem seals first because it's easier. If the replacement doesn't seem to change the misfire, I will eventually be moving to the leak then to replacing the rings.

Please, if you have any suggestions, feel free to add anything that will help me indicate this problem. Thanks for viewing and I will update as soon as I can.

Comments

  • JHMEE4JHMEE4 New Wagonist
    Why don't you swap the plugs out? At least change between cylinders. Swap cables? See if the misfire moves between cylinders. Much quicker than replacing seals.
  • Hmm, never thought of that. I was so frustrated and wanted the car to start badly that I didn't even think of that. I will be conducting the spark plug switch today then. Thank you. I will update as soon as I can.
  • JHMEE4JHMEE4 New Wagonist
    Another step would be to swap the injectors around and see if changes. Clicking is one thing, but a good spray is another.

    You may want to see if there's any leaks in the system. I sprayed carb cleaner around gaskets and meeting points to pinpoint leaks.kinda dangerous but it works if you know what you're doing.
  • klumklum Senior Wagonist
    bad cap and rotor maybe? lol - always pray thats the solution -30$
  • My first thought would be the injectors.

    Injectors don't like to sit for long periods of time without use. Sometimes just running them for a period of time can free up a stuck pintle, but if there is enough build up on the tip of the injector, it's not going to matter if it is clicking or not.
  • Update!!
    So I swapped the spark plugs as well as the wires around, still misses on cylinder 1. So I know my wires and plugs are good. I have also sprayed carb cleaner around the intake manifold gasket, no difference in sound or performance.

    I will probably swap the injectors next. If not, fuel lines are plugged?Dizzy is bad?

    Thanks everyone for their suggestions. I will update when i can.
  • I also forgot to mention, I popped open the dizzy cap and saw that there was small corrosion build up. I know corrosion build up in the dizzy is a big no no. But since I'm trying to save money, I do not want to buy anything for the dizzy yet until I know it really is the dizzy that is at fault.
  • JHMEE4JHMEE4 New Wagonist
    Fuel line would cause all 4 cylinders to misfire. Who knows maybe plugged just enough to cause a misfire since it's the farthest, would be a long stretch though. In other words, it think it's unlikely.

    Where's the corrosion on the distributor? Inside the cap? Or the distributor parts itself? Can always trying to clean up the cap.

    Ahh, last but not least you could always try a valve adjust too.
  • Clean the corrosion?
  • UPDATE!
    I just switched the injectors around this morning. Still, cylinder 1 still misfiring. So for sure, the injectors are working as they should.

    Now, it has to be the distributor that is the culprit. Yes, I have cleaned the inside of the cap. There is this little metal piece down the center of the cap(I think it's called a coil?). It was corroded there. I cleaned it off by sanding it down a bit. But looking at the rotor, it seems to be cleaned and not disturbed by corrosion very much. I should probably invest in replacing the cap and rotor though. That will be my next step, otherwise if I can find a whole obd0 distributor assembly at the junk yard or somewhere else for cheap, I will just go that route to replace it.

    @JHMEE4, I haven't done a valve adjustment in a while, but a little research will be no problem. I suppose I could try that before I go about on the distributor parts. I just read a forum saying that adjusting a valve has something to do with the compression--about it not being able to close if valves are tightened tightly. I mean my compression is 130 all around, so would it be worth my time?

    Thanks everyone for commenting and helping me to resolve this problem. I will update when I can. Minnesota will start seeing snow very soon.. ):
  • JHMEE4JHMEE4 New Wagonist
    You're right about the valve adjust, I forgot about your compression readings. My only concern with the whole distributor being at fault is thar you'd think all cylinders would misfire, since it's a part that all cylinders have in common. I'd start with the cap at the very least though, you never know if there's some small cracks that you can't see around the cap. I'll try to think of some other stuff that may cause cylinder one to misfire.

    What did the spark plugs look like anyways? Where they all the same?
  • JHMEE4JHMEE4 New Wagonist
    I'm excited about snow in Colorado myself! However, I know we won't get anything like you'll get in Minnesota! I plan on flooding the snow photo thread once we get snow. ;)
  • Cylinder 1 and 2 has carbon build up i believe. Cylinder 3 and 4 looked clean. I read something about valve stem seals being worn that causes the build up. If dizzy doesn't work, it's the seals that needs to be replaced.
Sign In or Register to comment.