Knocking, stumbling, and smoking.

Kahuna

Alright, I washed my motor off the other day with just the water hose and some degreaser... No big deal.

So I drove it town town everything was fine, until I took off at a redlight and it started stumbling real bad and would barely take off. So it finally stopped for a little while but started smoking pretty heavy and then it started stumbling again very badly. It would stop if you would let off the gas and the slowly press on it..

So my dad sugested I probably had water/trash in the gas, since the tank was lower than it has ever been. So I went to Walmart and got me a can of "Heet" and dumped in there, along with 2 gallons of 93 octane. (had maybe 1/2 gallon of 87 in there) Then I replaced the oxygen sensor. So, I started it up, didn't smoke but just a little, (probably because I was running open headers due to I had to take the header off to get to the O2 sensor)

So I got it all together, no more knocking, no more smoking. (only above 4k)(which is what it's always done that)

My question really is,
Why does my STOCK motor with just headers and a cold air intake detonate on 87 octane?

It doesn't make sense to me.

SiWagon

Been there.Done that. Sorry laughing at myself.

Your first sentence says it all.It's WATER in the distributer Cap.Usually goes away in a few minutes to overnite.Several causes:
1)Cap gasket bad(cracks,rips or disintegration) about: $4.
2)Cap is vented (hole or vent cap).Cover cap next time.
3)one of the grommets in the lower distributer isn't sealed all the way.play with it or silicone.
4) FREE Ignition upgrade(not the prob):
http://www.hondacivicwagon.com/board/vi ... .php?t=739

Haydz

As SiWagon says it is probably the distributor gotten a bit of water in it OR some water got down your sparkplug wells.

As for knocking on 87 octane.. sound like you are running lean. CHeck your fuel situation i.e. pressure reg and filter etc.

Kahuna

Yeah, I fugured I just got water in something..

But before this happend I started notice that it was knocking when under slight to heavy accel.

So I guess the 93 fixed it, but I don't understand why a motor made for 87 would detonate on 87?

Haydz

In all honesty i think your motors are made for 93. Anything above 9:1 really should be running on 98 RON (about 93 MON i think). I only run my RTi on 98 octane here, anything else runs like a pig.

If the problem has progressively gotten worse i would be checking out your fuel system to find out if it running leaner than it should be.

SiWagon

I've had several EF Civics.During Summer they'll on occasion get very light pinging.Try running through a can of injector cleaner(the cheapie Walmart brand) works fine once a year.Fuel filter needs replacement every 60K(96Km).
:idea: :arrow: Check for white corrosion on the inner cap tips & rotor tip too.