87 4kq - Still Idling badly (A little Long)

[Cade Carvell]

Hi all,
  I am still trying to figure out the odd idle problem.  When the engine
is warm, Idles badly, and causes hesitation (sometimes severe), but only
when the engine is warm and not cold. And I restart when this happens,
the engine hunts a buit for a good idle speed.  I also noticed that If I
come to a stop at he lights and have to wait, more then 30 seconds or
so, the engine starts to idle lower and lower, like it decided that the
current idle is to high (850-900 rpm).  I tested for Vaccum leaks VIA
wd40, and Propane, nothing for leaks that I can find in the engine
compartment.  I am going to try to do the Fuel filters this weekend,
found a big enough jack to do it.
   Anyway, I was testing the WOT sensor and the IDLE sensor's. I was
wondering if someone could check my results.  I think that the bently
agree's with these numbers, but I would really like another opionion.
  Anyway, looking at the connector attached to the head..From right to
left Pin 1, pin2, pin3, that is how I will reference them.
  1)  WOT Sensor Check:
   If I have a ohm meter on Pin 1 and 3, and push the WOT in sensor down
with my finger, I get a 0 ohm resistance, good, I think, that switch is
correct.  Anyway, If I test again with the linkage.  If I push the gas
pedal down / Push the linkage manually, and I go to WOT, I get infinity,
IE circuit appears open.  Is this correct?  I even tried, during the
manual engagement VIA the linkage, to push the WOT sensor closed, and I
still get infinity.  Can someone verify this...Thanks on this one.
  2)  Idle Sensor:
   Using Pins 2 & 3, with the engine off, I get 0 resistance, should be
correct.  If I manually move the linkage, a little bit (Width of a
Keyboard Period or a little more) I get infinity, I assume this is close
to 2 degrees, which should be correct.  I did notice that when I just
get to the edge of where the ohm meter goes from 0 to infinity, the idle
screw there, has a bit of a gap, should I adjust this screw that it
doesn't have a gap at the edge?

Thanks everyone for reading and helping me with this issue.

Thanks,


Cade Carvell
National Business Systems, Inc.
2919 West Service Road
Eagan, MN 55121
Office: 651-994-4400