Tuesday, July 21, 2009

Fixing a misfire during acceleration in a 1992 Honda Civic

I took some packages to the post office today, and was surprised to find my 1992 Honda Civic was having a very bad day. It was misfiring during acceleration at low-mid RPM. Idle was smooth and cruising was fine, but any normal amount of acceleration from a stoplight or stop sign produced an extremely loping, uneven amount of power. The car was drivable, but just barely.

I took out a couple spark plugs, and was surprised to find the gap had become huge -- around .075"! The plugs appeared to be worn out. I figured this had to be problem. I got some new NGK plugs, and unfortunately the problem persisted. I checked the compression in each cylinder, and they were all 150 psi +/- 5 psi. After a short consultation with my dad, I decided to replace all of the common ignition parts with real Honda replacements: distributor cap, rotor, and plug wires. This did the trick! The car was back to normal, and running strong. The original cap and rotor were Honda parts, but the plug wires appeared to be aftermarket (Prestolite). Dad and I agreed that aftermarket plug wires should be avoided altogether. Just bite the bullet, and buy OEM wires. They'll last much longer.

Even though it is difficult to see in this photo, the old plug (right) has a gap almost twice that of the new plug (left). This too-large gap in all four plugs might have contributed to the destruction of the plug wires.

3 comments:

  1. my dear stupid:if real,it apears that the central conductor in the spark-plug has worn off.it's a material defficency,not circuit fault.

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  2. Anon, you should read the blog post before making a comment -- replacing the spark plugs did NOT fix the problem. I should have just deleted your inane comment, but since this is the first non-spam comment that is worthy of deletion, I figured that I would respond one time to see what happens. Perhaps you were intoxicated when making the comment, thus impairing your ability to think and type clearly. Otherwise you might be a candidate for a brain transplant.

    ReplyDelete
  3. I like your post, I'm also having misfire issues with my 92 honda civic cx. Also liked how you handled that anon lol

    ReplyDelete