hey guys, 98 civic with 213k, got the plugs and wires changed at 170k, when i start the car,(esp when the motor is cold) the motor vibrates for about 10-15 seconds, then it quits and everything is fine, kinda like the motor is coughing i would say, could this be the plugs so soon??

Get some injector cleaner with PEA in it ..(drum roll with a ta-da) like Amsoil PI.

What type of driving does this car see?

mostly highway miles...been running techron through it every 4 months or so !

Not that I know specifically where it is on a Civic but this is indicative of a plugged Idle Air Control Valve. A common problem in 90s Hondas. Another common, easily fixed cause is air in the cooling system. Try purging it.

Well, that should have taken care of any deposits and your highway driving should make them take a long time to form.

I forgot to ask, did this happen before you changed the plugs and wires? Is that why you did it?

Assuming the answer is YES ...


Here's a test for you to perform. BEFORE you turn the key on (repeat BEFORE) place your foot to the floor and crank it for a few seconds. Stop cranking ..let your foot off ..and then start normally. It should not start when floored.

See if that reduces the misfire time to smooth.

no this was not happening before i got the plugs, just started about 2 weeks ago, usually happens in the morning,

Hmmm (sticking out lower lip and posing as a dumb version of "The Thinker)



Let us assume that one or more of the plugs is defective or gapped improperly.

Vibrates.then you say it seems like it is coughing? I'm confused. So how is the idle and when you step on the gas in neutral is the motor stumbling ??

Need more specifics and detail to help you. My first thought was a bad motor or tranny mount.

Mine too.

the motor seems well when i step on the gas, no hesitation at all..i just let the car idle for about 30 seconds and then its fine...

This seems fuel related. The spark plugs are not fixing themselves.
But on a cold start, your enrichment for the fuel may be faulty. Bad temp sensor, fuel injector[s], MAF sensor, vacuum leaks, etc..
Start with vacuum leaks. Every line and it's connection must be perfect [esp the PCV system]. No manifold leaks, either.

Sounds like the engine is fine to me.

I definitely think a motor or engine mount.

I know on my parents 94 Accord( 4 cyl, automatic) that when the car is cold at idle is makes the steering wheel vibrate more than it should, I know that on the web it has mentioned some kind of dampener (isolation mount) for the transmission is probably worn out...when the car warms up a bit heat reaches the mount area from the engine and exhaust manifold, and the vibration goes away.

the FIT valve and IAC valves on the hondas are known to "loosen" up and can be fixed . there is a very detailed sticky on superhonda about this...remove it and screw the plunger back in.....

here is the link w/pics and instructions:

http://www.superhonda.com/forum/f55/troubleshooting-idle-problems-259965/

IAC cleaning link:

http://www.superhonda.com/forum/f94/diy-cleaning-your-iacv-144463/

Did it get extra cold 2 weeks ago? Sounds like a typical IACV getting gummed up...