How to tell which distributor I have in my 1991 Honda Civic LX 1.5L

SOURCE: timing marks for a 1995 honda civic lx

did you try google thy check there images that alwas helps

SOURCE: 1991 Honda Civic 1500 idles irregularly, with check engine light.

I think I would suspect the fuel injectors, especially since that is the code you are getting. Fuel injectors clog up, get dirty, stop working the way they should. They can be cleaned (you can remove them and send them to a company that cleans them and makes them like new, or, they can be cleaned in the car by some garages, or, you can get a can of Sea Foam spray and spray it into your throttle housing several times to try to do some cleaning that way, or, you can dump a can of Sea Foam (non-spray) into your gas tank and run it with the fuel through your injectors). You should probably check when you first start the car to see if you are getting any leakage from one or another injector (one or another may look moist or wet if the seals are leaking). You can also do the long screwdriver test (hold the bit of the screwdriver against each injector in turn and listen with your ear against the other end to see if each is clicking regularly). I would try the Sea Foam first.
I hope this is helpful in getting you started on a fix.

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