poor idle on 4kq

[Doyt W. Echelberger]

Try taking the patch off and see if your idle problem goes away.

If the idle returns to "within factory specifications," then look for and 
correct obstructions/restrictions to the air flow through the induction 
tube from behind the passenger headlight region.  That tube may have a 
hornet's nest, or a loose flap of tube liner, or just be collapsed 
somewhere along it's length past the point of your patch.

I had an 86 4kq with a similar very deteriorated "cold air inlet tube."  I 
drove the car through some flood water and the engine slurped up about a 
quart of the flood water and hydrolocked the engine, bending most of the 
rods.  I had to replace the engine.

Good hunting.  Doyt Echelberger
 >>>>>>>>>>>>>>>
At 08:30 PM 10/2/00 -0700, you wrote:
Problem with an 87 4kq:
poor initial idle
..snip....  Just to see what it
would do, I duct tapped up a rather large hole in a very deteriorated,
what I believe is called, "cold air inlet" a rubber ~3 inch tube that
makes a 90 degree bend below the air box.  ...snip....Anyway the real 
problem is that now
that I have closed up the leak in the hose, the car idles very poorly
when initially started from cold. It starts ok and then immediately
begins to oscillate between ~1400 and 300 rpm with a period of a few
seconds.  At the bottom of the range it sounds like it is going to die
and I have to give it some gas to bring the engine speed up.  After it
has warmed up for a short time the oscillation goes away and everything
seems OK if perhaps a little rough. Does anyone have any ideas of what
to check?  I don't know for sure but would not be surprised if this car
were on its original O2 sensor.

Thanks for the help

Luke