Re: rough idle

[rjandrew@post.cis.smu.edu (R Justin Andrews)]

> 
> Well l,  I did the oil dipstick test and the engine did not die.  Does this
> mean that I can assume there are no (major) vacuum leaks?  Also when I
> disconnected the idle stabilizer valve the engine still ran rough.  Does this
> mean that the problem lies elsewhere?  The roughness has actually spread.
> When I accelerate during one of these rough idle spells,  the engine
> sputters up until about 2500rpm where it smooths out.  Sometimes when I'm
> cruising at about 75mph or so I can feel a slight hint of a surging but just
> barely.  Is there anything else I should try before I bring the car into the
> shop?
> 
> Jesse Almero, Jr
> Torrance,  CA
> 1986 Audi Coupe GT
Had the same exact problem with my mom's 86 5KS turned out I thought the fuse 
for the idle stabilizer circuit was an extra..... NOT that would be my first
check, put a fuse in every socket that looks like an extra, one is NOT! 
If this fails, let the car idle, then unplug the idle stabilizer valve,
if it stalls or nearly stalls then, your ISV is working fine but may need
cleaning or a hose, try cleaning it first, if this does not work, check
the hose, I mean CHECK IT!!!! don't just look at the top of it and say,
looks fine to me, NO WAY! there will more than likely be a tear under the
hose (on the bottom that you cannot see without taking off. (happened to 
me twice) Well, back to if you unplugged the electric connection to the 
ISV and there is no change and you checked all fuses and fuse slots,
Get a new ISV relay after cleaning the ISV.
Hope this helps,
Rich Andrews
rjandrew@post.cis.smu.edu