help with a 1986 volvo 240 wagon

[ofgoddessstature]

the volvo has always had a small rattling/clunking sound that seemed to
be coming from toward sthe rear of the vehicle (didn't think it was a
big deal since it just passed emissions and inspection) and yesterday
when i was driving home from queens the noise stopped and then a few
minutes later there was a sharp decrease in my gas milage and the wagon
lost the ability to accelerate so it kinda of just maintained a
constant 20-30 mph and it was making this "whoosh"ing sound every time
i hit the gas pedal, as if something was being sprayed. its not leaking
so i don't think it's the fuel line. maybe an exhaust issue? i'm
totally in the dark. all i know is that the car needs to be up and
running soon so any help would be appreciated. thanks.

 

[Duane]

Wild guess: Catalytic converter internals finally let go all the way and is
blocking your exhaust.

Duane

 

[zoltan]

Sounds like possibly a fuel pump going (or gone) bad? They are in the
rear of the car and in the gas tank. Might be combined with a clogged
fuel filter. Definitely sounds like the engine isn't getting enough
gas though.....

 

[Michael Pardee]

Wild guess: Catalytic converter internals finally let go all the way and
is
blocking your exhaust.

Duane

Not bad for a wild guess. The Haynes manual for my daughter's '93 Accord has
a nice test for exhaust restriction:
*connect a manifold pressure guage to the intake manifold
*start the engine and open the throttle enough to bring the rpms to about
2000 for a few seconds
*suddenly release the throttle and watch the guage
If the guage returns to approximately the idle reading within two seconds,
the exhaust is clear. If the guage hangs around the 2000 rpm reading for a
couple seconds or returns to the idle reading very slowly, the exhaust is
restricted. Note that the restriction can be in the cat or in the muffler,
and taking things apart is the only way of telling where it is. We had an
'82 Toyota that had a melted cat, and when we got it off and tried to blow
through it the restriction was as bad as you'd get from a soda straw. The
engine started and idled okay, but didn't like to rev and spit gasoline
spray out the carburetor when the throttle was opened.

Mike

 

[James Sweet]

Wild guess: Catalytic converter internals finally let go all the way and is
blocking your exhaust.

Duane

This happened to my mom's '86 240 years ago, it was rattling like crazy
for months, I pulled the cat and dumped the broken bits out and put the
empty shell back and haven't touched it since. Amazingly the emissions
test still comes out very well, great engines, very clean burning.