91 Accord engine started to miss last night

Very odd. the engine started to miss (sounds like one cylinder is not
firing) for about 1 minute. It went away for 5 minutes, then came
back, I replaced the plugs (they didn't look too good anyway), but it
didn't help.

Has anyone run accross this before. My first thought is the plug
wires /dist/rotor, just need to be pointed in the right direction.

Thanks

Thom
91Accord EX, 169,000 miles

 

You are on the right track. Things you can do to nail this
effectively and economically:

If the wires do poorly on a resistance check, replace. If
you do not understand this, ask away.

If the wires are more than five years old, replace.

How old are the cap and rotor in miles and years? Are they
OEM?

Use only the OEM recommended spark plugs, and only OEM
wires, rotor and cap. These pay for themselves in the long
run. (Believe me, I am cheap and learned the hard way.) They
do make a difference in performance.

Regular poster here "Tegger" has a site with much good
wisdom on it. See in particular
http://www.tegger.com/hondafaq/faq.html#startrun

Elle
Original owner, 1991 Civic, 201k miles

 

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First telltale sign on a '91 might be red rust coating the inside of the
distributor cap. The bearing goes bad and starts leaking dust. When it
seizes, the timing belt breaks and you get a different car.

How often do you use injector cleaner? Might just be a sticking injector
too.

'Curly'

 

That red dust was actually more a '92-and-up problem. The distributor was
changed for '92 to mate with the all-new ECU. It's still worth checking for
red dust, of course...

 

Is your Check Engine light on?

Have you checked to see what the spark looks like? Is is purply-blue?

How old are the wires, cap and rotor? Are they OEM or aftermarket?

 

Cap and rotor were way old, I assume. Before I bought it. We were
testing the spark on #2 cylinder, when we removed the wire, the car
quit. Either we smoked the distributor, or it doed right there. We
replaced it, and it is back to running bad, but it is running. We
have tested the spark on all the cylinders, it is nice and strong, but
number 2 cylinder is real weak. A compression test has revealed low
to no compression on that cylinder. Looks like we burned a valve or
something.

 

:

Before you condemn the valves, check their clearances. You might get lucky
and the valve is simply being held open and not yet burnt.

 

I thought these enginse were interference engines. Wouldn't the
piston slap the valve it it were being held open?

 

They /are/ interference engines.

But when I say "held open", I mean by one or two thousandths of an inch.
That's more than enough to cause poor compression and valve burning with no
danger at all of the piston hitting the valve.

Pistons whack the valves when the timing belt breaks, not when the valve
clearances are off.