'95 90Q - besides injectors, ISV, or vaccum leaks......what else could be causing my lean fuel mix?

[Elliott Potter]

Joel Lenorovitz wrote:
> 
> '95 90Q with recurring check engine light due to lean fuel mixture in banks 1 and 2
> 
> I've had the injectors replaced under the recall, cleaned the ISV (which seemed to
> cure my intermittent idle drop problem), and examined all I can see for vaccum
> leaks.  Interestingly, even if I intentionally create a huge vaccum leak I cannot
> reproduce the condition that sets off the light.  What else could be causing this?
> What else can I check?

Oxygen sensors?  Clogged intake passages around the throttle body/intake
manifold?  
When you pull the codes, what do you get?  How is your idle quality? 
When does the check engine light usually come on (how do you reproduce
the condition while driving)?

> Also, how much oil does the V6 12v typically consume?  I don't see any evidence of
> leaking, but the level sure goes down rapidly - perhaps 1/2 to 1 quart per month.

It varies, though usually earlier V6's consume more than later ones. 
How many miles in a month?  1 quart / 1000 miles seems to be the
"acceptable" limit for older V6's; by "acceptable" I mean if you take
your car to the dealer and say "my car burns 1 quart/1000 miles" they'll
say "that's normal."  More than that, start looking for leaking seals or
be thinking about new rings.  You might consider pulling spark plugs to
see if they're fouled, though if you have lean/rich problems you want to
sort that out first.
--
Elliott