Poor Fuel Economy - 95 Camry

Hello Folks-

I have a 95 Camry with 130,000 miles on it, recently the gas
mileage has been going downhill. The tank holds 15 gallons and the
last fill up did barely 300 miles, about 20mpg.... Any suggestions as
to where to start? Maybe a list of things to check? I searched this
group and came up with some ideas: checking an Oxygen Sensor, checking
for cracks the air intake tubing, other ideas anyone?
A few bits of history that might help. Several months ago I
fixed a leaking fuel line (vapor return I believe, much thanks to Ray
O), recently I reinstalled the oil drain pan and had to remove various
exhaust parts, I was a little questionable about how snuggly I got
things back together, the car doesn't sound "louder" to me, but could
a "leaky" exhaust system affect the fuel economy? The service records
on the car shows the spark plugs, wires, rotor, and disrupter cap all
replaced within the last year. I have no idea the quality or make of
the wires/plugs that were used, what are some opinions on the type/
make of the wires/plugs that should have been used? I see such a
range in prices for these items, is the price for the higher quality
justified, I seem to be getting mixed signals.

Any ideas would be greatly appreciated!

Sincerely,

Blake

"blake18" <zachenos.TakeThisOut@hotmail.com> wrote in message
news:1171514266.423368.50410@m58g2000cwm.googlegroups.com...
> Hello Folks-
>

Some more vehicle info please...

4 cylinder or 6 cylinder engine?
Automatic or manual transmission?
What is your usual MPG?
What kind of driving do you do, i.e., city, highway, hilly terrain, etc.

More comments below after pertinent sections...

> I have a 95 Camry with 130,000 miles on it, recently the gas
> mileage has been going downhill. The tank holds 15 gallons and the
> last fill up did barely 300 miles, about 20mpg.... Any suggestions as
> to where to start? Maybe a list of things to check? I searched this
> group and came up with some ideas: checking an Oxygen Sensor, checking
> for cracks the air intake tubing, other ideas anyone?

Did you calculate mileage by dividing miles driven by gallons filled?


> A few bits of history that might help. Several months ago I
> fixed a leaking fuel line (vapor return I believe, much thanks to Ray
> O), recently I reinstalled the oil drain pan and had to remove various
> exhaust parts, I was a little questionable about how snuggly I got
> things back together, the car doesn't sound "louder" to me, but could
> a "leaky" exhaust system affect the fuel economy?

A leaky exhaust generally will not cause poor fuel mileage, although you run
the risk of carbon monoxide poisoning, asphyxiation, and failing emissions
tests with a leaky exhaust.

The service records
> on the car shows the spark plugs, wires, rotor, and disrupter cap all
> replaced within the last year. I have no idea the quality or make of
> the wires/plugs that were used, what are some opinions on the type/
> make of the wires/plugs that should have been used? I see such a
> range in prices for these items, is the price for the higher quality
> justified, I seem to be getting mixed signals.
>
> Any ideas would be greatly appreciated!
>
> Sincerely,
>
> Blake
>

I believe in using OEM ignition parts - plugs, wires, rotor, distributor
(not disrupter) cap to avoid drivability problems. Some aftermarket
ignition parts work fine, some do not. I don't like experimenting, so I
recommend OEM. I have not seen aftermarket ignition parts cause poor fuel
mileage so I doubt if that is your car's problem.

OK, now for stuff to check in the order of likely cause of the problem and
ease of checking:

Check the air pressure in the tires (now is a good time to check the spare
while you are at it). I recommend inflating the tires about 3 to 5 PSI over
the manufacturer's recommended tire pressure to improve tire tread life and
fuel economy, with the tradeoff being a slightly harsher ride. I fill the
spare to the maximum listed on the tire and keep a tire pressure gauge in
the car. If I have to install the spare, I can use the gauge to let air out
of the spare if necessary.

Check the air filter to make sure it is not dirty. If you hold the air
filter element up to a light, you should be able to see the light clearly.
If the light is dim or you cannot see any light, change the air filter.

Check the mass air flow (MAF) sensor. It is the only device with wires
sticking out that is attached to the air filter housing. There is a tube
that protrudes into the air flowing out of the air filter, and inside the
tube is a fine wire. The MAF sensor is not supposed to be serviceable, but
you can try gently cleaning it with carburetor cleaner. Do not break the
wire inside the tube or you will be looking for a new MAF sensor for big $$.
Spray the car cleaner, let it drip dry, or maybe you can GENTLY swab it out
with a q-tip.

If the MAF sensor is really greasy or oily, change the PCV valve.

My guess is that low tire pressure, a dirty air filter, and a dirty MAF
sensor are combining to give poor mileage.

Check the condition of the automatic transmission fluid. It should be red
and translucent. If it is black or brown or smells burnt, think about
getting it changed soon. Do not get it flushed if you elect to change the
ATF.

Check the brakes to make sure they are not dragging.

Check ignition base timing.

Hope this helps, let us know how things work out.
Good luck!
--

Ray O
(correct punctuation to reply)