I have a 1987 honda civic, carbureted 1.5 engine.
I am battling with an idle misfire that I can't seem to resolve.
Heres how it looks, the idle fluctuates rather than holding steady by maybe 100 rpm, Intake vacuum is not steady but bounces between 17.5 and 16.5 "hg, it does become steady at higher rpms. The exhaust pressure at the tailpipe is steady for a few seconds and then makes a "puh" when the pressure falls off.
I checked my O2 sensor output voltage and it seems to indicate a lean condiition at.1 volts, but closing off the choke makes the sensor respond quickly up to.9 volts. I put a spark plug test light inline with each spark plug 1 at a time and the lamp glows pretty steady but will occasionally glow brightly. When I rev the engine up to say 2k rpm the lamps is always bright and there is no sign of a misfire.
new plugs, cap, rotor, wires.
In desperation I replaced the ignitor.
plugs are denso, cap and rotor are quality parts, the wires are the top shelf wires from aurtozone.
I suspect my carb is the cause of the lean condition, but the weak spark has me concerned that my distributor may be shot.
I checked the ignition coil resistance and it is really close to dead on with the factory service spec, I pulled the coil wire from the cap and the spark jumped about an inch and was reddish blue. I then pulled the wires (at the cap) to each plug and they acted the same, they would jump about an inch and were the same color as the coil spark. The wire that had the test light in it seemed to give a brighter glow when I held the connector a little out of the cap.
What should I do?
have the same problem?
Tuesday, December 5th, 2006 AT 4:49 PM