Infiniti: 1992 Q45, mileage deteriorating badly but runs OK

I have a 1992 Q45, and used to get 17.5-18.5 MPG no matter what I did. Now I am
seeing 14 MPG and now sometimes into the 12s. Performance seems unchanged.

The car has 120K miles and I am trying to plan a keep /sell strategy, so it has
not yet undergone the 120K mile service. Also, it has not had the chain tensioner
replacement. I have in mind some budget for the chain tensioner, but am asking
this group for some insight on the mileage problem. Is there a likely culprit ?

George

In article <supernews.com>,
George Pontis <net> wrote:
 

I have a '91Q and the cold weather makes it run richer till it warms up.
When I use a tank for strictly short trips, I can get as little as 13
mpg. Hiway as much as 21.

m-m