1995 SL Missing Cyl.

Missing cylinder sporadically...

Newish plugs, newish wires... Felt like it was running on 3.5 plugs for a
month, now it feels like 3 plugs the entire time...

I've heard it could be a simple sensor, but I've also heard it could be the
oil eating habits fouling the plugs. Any "first things to check" I
should... er.... check?

Joe in Northern, NJ - V#8013-R

Currently Riding The "Mother Ship"

Ride a motorcycle in or near NJ?
http://tinyurl.com/5apkg
http://www.youthelate.com

 

If you have already swapped plugs and wires and that it is getting
"fire" to plug and it still drops same cylinder, it is time for a
compression check before you go any further.

 

Sure Joe,
remove the plugs and check for carbon buildup. It might not hurt to
clean them up a little with a wire brush then regap them to .040
(Hmmm.... for '96 only, the gap was specified to be .060) Either that
will improve things greatly, or will make no difference at all. Well
then we'll look elswhere....
Is the 95 SL single or dual overhead cam?
Throttle body or discrete (4) fuel injectors?
It might be an injector. I think I had a wonky one but it straightened
itself out (apparently)
It would start on 3 cylinders and It missed consistantly until the
engine warmed up - almost to the same few hundred feet on the same road
every morning on the way to work... One day it just started on all 4
cylinders and the problem was gone. Cool. (But no CLOSURE...)
I'm guessing that it is a bad wire, though. They can look fine and
still be misfiring. The Saturn ignition system is so "high energy"
that the spark can find its way from the wire core and to ground (ie.
cylinder head or valve cover) through microscopic cracks in the
insulation.
I remember seeing it myself once - at night - the spark was jumping to
the valve cover. But since the valve cover is insulated with a nice
gasket, the spark was finding its way to ground by making a jump to the
bolts that hold the valve cover on. (apparently the washers are
plastic or gasketed too) But every valve cover retaining bolt had blue
sparks dancing around them. Cool man.... watch it... its just like
lightning, dude....

You know the Saturn has a "waste spark" system, right? If one plug is
messed up or shorting - it can affect its corresponding "coil mate"
too, 'cause every time #1 fires, so does #4 and every time #2 fires, so
does #3.

-Wavy
fighting the forces of entropy
One Saturn at a time....

 

CLIP

wavy,

Thanks for the god info. Bottom line is I commute 70 miles daily so the car
got dropped off at the shop last night... I'll pass the info on to him and
see how low my bill can be kept.
--


Joe in Northern, NJ - V#8013-R

Currently Riding The "Mother Ship"

Ride a motorcycle in or near NJ?
http://tinyurl.com/5apkg
http://www.youthelate.com

 

The 0.060" gap for '96 was an error. It also should be 0.040". In addition
to other suggestions, clean the throttle body thoroughly and remove and
clean fuel injector connectors too. Good luck.

Bob

 

To finally answer the original post - as well as this new one, I boldly
proclaim that...

The problem was an oil fouled plug and collapsed PCV valve tube / bad PCV
thingy...

Oil fouled is in that realm...

Sand blasted 'em, but the ceramic was cracked... So I replaced it. Cyl #3
if it matters.

Single in my case.

Not sure...

No kidding... My "coil manifold thing" has a slightly corroded leg... A
plug wire was allowed to arc for about 5 years by the previous owner... So
I have smaller problems all the time.
--


Joe in Northern, NJ - V#8013-R

Currently Riding The "Mother Ship"

Ride a motorcycle in or near NJ?
http://tinyurl.com/5apkg
http://www.youthelate.com