1990 Accord LX Misfire Problem
 

Hi All!

My ’90 LX just developed a misfire problem today and I’m hoping
someone may have some insight.

1990 Accord LX, 5-Speed, 127k miles.

I’m no pro mechanic, but I’ve done most of my own work on my cars and
motorcycles for the last 25 years. I definitely know my arse from a 12
point, 3/8" drive, Snap-On Flank Drive, deep socket.

Anyhow, here’s the story... I replaced my radiator last week due to a
small crack in the top tank. While I was at it, I also replaced the
radiator hoses and the thermostat. I was very careful to put
everything back in as it was supposed to be and the job turned out
ok... no leaks and the car ran fine.

Today, when I was getting off the freeway, (highway, for those of you
outside CA) I felt the car misfiring/skipping, like it wasn’t running
on all 4. It was not a totally constant misfire, through all RPMs and
loads. Most noticably, it did it at low to mid RPMs, under medium
load. The idle would fluctuate from normal to misfiring. I could get
the car to buck pretty good at part throttle, 3rd gear, accellerating
moderately. The car started back up ok after making a few stops too.
No check engine light.

I already took care of the obvious and changed out the cap, rotor,
wires, and plugs, but no luck. All wires and hoses in the areas I
worked on were also double checked... everything was connected and
tight.

When changing the spark plugs, a couple of them were only finger
tight, but no signs of compression burn-by or anything like that. I
gapped the new ones at .044", used some copper anti-sieze on them,
and torqued them properly. Also possibly worth noting... there was
some oil on the plug boots down in the holes and also a little bit in
the very bottom of the distributor, but not really enough to worry
about.

So, the car continues to misfire.

Is there anything obvious that I may be missing?

What sensors are in the area of the lower/rear radiator hose that I
may have knocked into and possibly should re-examine?

Any other thoughts?


TIA! -Joe