1996 Honda civic DX with after market muffler. Vehicle started making popping noises and engine will shudder/jerk from time to time. This happens during idling, decelerating or accelerating. The issue started after refueling the vehicle. The vehicle runs on grade 91/ premium gas. Coasting with no problems. The popping sound will only start when the vehicle reaches the normal operating temperatures. Spark plugs and wires were replaced 2 months ago and is in good condition. Does not seem to be a misfire due to it drives smoothly except when accelerating or decelerating. I am stumped and need opinions on the matter.

 

Exhaust leaks are easy to check by blocking the tailpipe for a few seconds with the engine idling. Pressure should build up quietly. A small leak will make a hissing sound from where it is under the car. A big leak will not let pressure build up at all.

Misfiring with heavy throttle low rpm is almost always weak sparks. There are some really lousy aftermarket wires out there that only last a few months.

You don't need to put 91 octane into a stock DX engine.

 

grabbed some denso wires for like 30 bucks.
ngk want $40 so screw em
all things denso ftw :lol:

 

Appreciate the inputs. I am not that mechanically inclined but i will try out some of the inputs you have given me. Will keep you guys posted.

 

Status update, still doing some self diagnosing and tried stuffing rags on the exhaust as it runs and she still pops/hiccups like its trying to stall. Also i noticed the exhaust was really dirty like soot black when i removed the rags. Another thing is that it smells like gas is coming out of the exhaust. Does that mean that im running too rich and not getting enough ignition? Will try to replace spark pkugs and wires. What do you guys think?

 

When an engine misfires, raw gas will come out the exhaust.

 

screw everybody and their overpriced parts, **** quality we want the cheapest a dollar can buy. give me that junkyard spark plug

 

check vacuume with a guage, or map sensor voltage in relation to idle. If low, stuck egr may be your culprit. 2 things can cause a rich condition. Too much fuel obviously, or too much air not allowing to cause a flame front.

 

Status update 2. Sparkplugs 2 and 3 are melted and stuck at the chamber. Took me awhile to take it off and clean it then replaced plugs and wires. Let it run and idle till it got to normal working temperature and she is golden. Seems like having those sparplug boots melted and stuck in there was the root cause . She runs like a champ now. I appreciate you guys giving me advice.

 

Too much air induces a lean condition, not rich. (EDIT: For what it's worth, too much exhaust back pressure from a restricted cat or other restriction can make it go rich)

I'm glad you found the problem but I would recommend taking a look at WHY your 2 month old ignition wires melted. Even if they were crap wires they shouldn't have "melted" especially in such a short time. Most likely culprit would be contamination by some kind of petroleum product, ie a leaking spark plug tube seal. If there was any oil on the tops of the plugs, in the spark plug tubes or on the ignition wires you may want to go ahead and change your valve cover gasket. Make sure you get the set with the spark plug tube seals and I always like replacing the grommets as well while I'm in there (but you usually have to buy the grommet set separately)

 

[QUOTE=adamhunsicker;51459847]Too much air induces a lean condition, not rich. (EDIT: For what it's worth, too much exhaust back pressure from a restricted cat or other restriction can make it go rich)


Nice easy fix. Too much air does cause a lean condition. However, if it does not produce a flame front, what comes out of it is rich. O2's can fool you that way once in a while. Glad to hear it was something simple.

 

Checked for leaks or anything but the chambers were clean but i will replace the valve cover gasket and the grommets. I applied dielectric silicon grease on the boot and all the good stuff. I will be keeping and eye on it and hopefully it'll last longer.

 

The boots should be made of oil-resistant rubber so oil in the holes is not the end of the world. Actual melting from heat would be because the spark plug was loose, allowing hot gasses to blow out of the cylinder, or from general overheating of the engine.

 

Talking about loose spark plugs, when i was replacing them the 2nd and 3rd chamber spark plugs was actually very easy to remove especially the 3rd one it felt like it was not even tightened. Those some good info. I am learning a lot. Thank you guys.

 

Gotta say if the plugs were that loose I'm surprised you didn't hear or feel it. Usually when one comes into the shop with that problem I can go straight to it because of the sound it makes.