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?
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.
----------------- The SnoMan
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....
Joe wrote:
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. :)
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.
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