puzzled (was stumped)

["Greg Woodard" <gwoodard@ndsuext.nodak.edu>]

Again thanks to everyone that has offered help on my problem.

Eric, put me unto what I think is the correct path.  He suggest that 
the coolant temp sensors may be causing the problem.  We checked them 
lastnight.  The one that I suspect is causing the problem, or at 
least is a part of the problem, tested 3000+ ohms cold.  Warmed the 
car up, to where it was starting to miss, 15-20 minutes.  I pulled 
the connector off of the sensor, and the car started to run the way 
we have come to expect this car to run when it is warmed up; (really 
bad).  Measured the resistance of the sensor, less then 120 ohms.  
Put the plug back on and the engine smoothed out a bunch (still not 
like it should be).  Then just for fun I pulled the plug off again 
and jumped the two connectors (0 ohms).  Engine ran perfect.  My son 
drove it around for 15 minutes- perfect.  He then took it on the 
road, 15 miles to the town where he goes to school- no problem.  
Drove around for over two hours- no problem.  Drove home - no 
problem.  Started right up this morning (46 degrees), but quit three 
time, as would be expected running full lean.  

So now I'm puzzled, the sensor seems to check out ok, but also seems 
to be the problem.

Thoughts anyone.

Greg
gwoodard@ndsuext.nodak.edu