[s-cars] Occasional Smoking

[Brian Pleet]

My 90 90Q seems to know it's approaching 250k km by acting her age.

For a few weeks the idle went wild, she belched (white) smoke erratically,
she'd threaten to stall (but never did) on deceleration.

Having gained my full attention, I did a compression test, followed by a
leak down test;

   - #1 9.6, 10, 6,6
   - #2 10.5, 7
   - #3
   - #4
   - #5
   -

Followed by cleaning the ISV, replacing the O2 sensor, replacing the rotor
and cap and put it all back together. For the past 3 days she's been
purring...except

The plugs are covered with a black dry soot and it smells of hydrocarbons.
If I measured mileage  it appears to be down. Oil consumption is normal,
perhaps a little elevated.