UPDATE #2 Re: Misfire on cyl. 2

Doug Yoder yoderw at msoe.edu
Tue Jul 5 23:18:14 EDT 2005

Ok, after some experience driving this weekend, the car (1991 100, 2.3l 
NF engine) is still running very poorly.  Significant loss of power 
(lose ~5mph going up hills on the freeway, can't accelerate) and fuel 
economy (~12 MPG!), and rough running - seems like cylinder #2 isn't 
firing, unplugging its spark plug wire doesn't change the idle.

After about 300 miles since the new spark plugs were installed, I pulled 
#2 to look at it again.  *Significant* oil fouling.
Picture here: http://people.msoe.edu/~yoderw/stuff/oiled_plug_small.jpg
(24kB, 640x480 JPG)

So I started thinking how oil could be getting into the cylinder. 
Piston rings, head gasket, or valve seals.  Rings or head gasket would 
show up on the compression test I did last week, so that leaves valve 
seals.  Am I missing anything?

Another question (somewhat rhetorical, but...) is "why did this happen 
all of a sudden when I changed the oil, plugs, and dist cap/rotor?"  I 
checked the oil level after seeing the fouled plug, and it was a quart 
too high!  Now, I know I only put in 5 quarts, because I only *had* 5 
quarts... and there's only 5 empties in the garbage.  4.5 quarts came 
out, just like normal.  I drained a quart out, and it looked/smelled 
normal - no coolant or anything in it.

This evening I tried pulling the ECU codes again, and had better luck 
than the last time I tried it.  One weird thing, though, was that once 
the blink output was activated, the idle became very rough and the 
engine died shortly thereafter.  Found one code: 2223 = altitude sensor. 
  Anyone ever hear of an altitude sensor going bad?  I'll check the 
wiring on it tomorrow.  It seems, however, that the oil in cyl #2 and 
the altitude sensor would be *completely* unrelated problems.

Any suggestions?  Thanks in advance,
-Doug Yoder

|    Doug Yoder    |   wdy at zordok.net   |    http://www.zordok.net/    |
|  Don't tell me the sky's the limit...                                |
|                                  ...there's footprints on the moon.  |

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