I've had an unstable idle on my 92 940 turbo
since I had to replace the engine. Now it's been
about 45,000 miles and nothing done has helped for
long. Mostly the idle speed is too low, which leads to
stumbling. In nuetral, the idle varies between 500 and
1200. Recently a new symptom has
emerged -- when cold (less than 45 degrees) and on first start-up,
the engine misses on one cylider for about thirty
seconds then evens out. Also this stumbling is now
getting annoying, or at least my patience with it is gone.

When underway the engine runs just fine, doesn't burn oil, spark
plugs look normal when removed; we've tried replacing idle motor,
throttle position switch, etc. to no avail. Injectors were
switched out with older ones on had with no change. Valves
were adjusted properly. If only there
was an idle adjustment screw my problems would be solved
(I can hold 750-850 rpm with the acelerator pedal
with car in gear, if i use the set screw on the throttle housing
the idle zooms up to 1800 in neutral, so that's no good).


Ed N.