blown cylinder?, or easier fix?

i have a 91 accord with 230K..i recently pulled up to a toll booth,
and the car sounded like it was missing...a knowledgeable friend gave
it a spark test, and guessed that the car had blown a cylinder...i’ve
been running it locally, and it’s been getting me around...it idles
very rough, but when i get it over 20mph, it seems to smoothe out and
runs fine...any thoughts on this problem...is it cylinder, or an
easier fix...thanx for any suggestions...

 

blown cylinder???

before jumping to such expensive conclusions, get a little data on your
side:

1. check the ecu for codes.
2. eliminate problems: make sure all the plugs are screwed in correctly,
that the rest of the ignition componentry works ok, etc.
3. if 1 & 2 doesn't lead you to a fix, and it likely will, do a
compression test.

report back with results.

 

As jim says - a failed cylinder is not the first thing we think of. If the
temperature is steady I wouldn't even put cylinders in the first bunch of
suspects.

If the power seems normal above 20 mph, add a check for vacuum leaks
(particularly cracked hoses to the intake manifold) to jim's list.

Mike

 

bad injector?

 

hi...this is minique once again...will have compression test done
tomorrow...mechanic said it could be bad valve,worst case scenario,
which would require valve and gasket job, taking it over 500
possibly...he said it probably would not be worth it, due to high
mileage. a month down the road it could happen to another valve...u
never know....best case scenario, a bad rocker arm, which he could fix
for around 100....stay tuned for the climactic ending of this
saga...and thanx for the feedback

 

A bad valve would be bbad all the time. Look at the earlier
suggesteds possibilities. I had a VW Golf with a blown valvew,
beleieve me it does not get better with speed.

 

Good point - that would be unusual.

 

Yeah, anything that would be considered a "blown cylinder" wouldn't clear up
with speed. I'll third the recommendation of a compression test and searching
for vacuum leaks.

Oh, and most importantly, get a second opinion from another mechanic - this one
sounds like he's looking for ways to uninstall your wallet.

 

burnt valves do "clear up with speed", or while the burn is still small
at any rate. but there's no sudden onset. i think the o.p. simply had
a plug unscrew itself - it's sudden, sounds dramatic, and because
there's no compression, the car still runs at speed without to much
drama, albeit with reduced power.

 

the way u are describing it do a compretion test i just replaced a exaust
valve on my 90 honda accord 2.2 it was burnt it still ran on 3cyl. at a
idle it ran bad it shook the car it would still go on the highway up to
speed and it ran ok but as soon as it idled it ran bad if i remember
wright the valve cost $18 and the gasket kit cost $130 and i did the work
my self what a pain in the butt it was. if they want to charge u more than
$350 to fix your cylinder head get a rebuilt one at advanced auto $361.99

 

yep...that’s what it was...hoping it was just a rocker arm, but
cylinder #1 had 0 compression, and no visible ticking sound.....also ,
had a little oil on the plugs...thanx for the advice, but i dont think
i could handle the valve job myself...anyone wanting a parts car, let
me know...will use it to get around locally for a while until i can
find another vehicl