Oxygen Sensor starting to go?

[Pete B]

Dear Lexus Experts -
Have just started having some intermittent problems with my 2000 ES300
(58,000 miles, Northeast USA) turning over OK on turning the key, but not
"catching". The car immediately stalls out, and it sometimes takes a number
of tries and depressing the gas pedal until it idles on its own. As usual,
once it's running, it's smooth, quiet, and performs as I would expect. Any
ideas on what might be failing?

Thanx,
Pete

[Ray O]

Post by Pete B
Dear Lexus Experts -
Have just started having some intermittent problems with my 2000 ES300
(58,000 miles, Northeast USA) turning over OK on turning the key, but not
"catching". The car immediately stalls out, and it sometimes takes a number
of tries and depressing the gas pedal until it idles on its own. As usual,
once it's running, it's smooth, quiet, and performs as I would expect.
Any
ideas on what might be failing?
Thanx,
Pete

Several things can cause the symptoms you are describing. Check the air
filter to make sure it is not clogged and the passage out of the air filter
does not have any debris accumulated in it.

The cold start enrichment system may not be working. Check to make sure the
coolant temperature sensors are hooked up. If you have a volt meter, check
for increasing voltage out of the sensors as the coolant warms up.

Check the MAF sensor to make sure there is no gunk accumulated on the wire
inside the tube that sticks out into the air stream.

If all that stuff checks out, have the fuel pressure checked to make sure
fuel pressure is not dropping while the vehicle is parked. If it is, check
the fuel pressure regulator.

[Pete B]

Thanx Ray.

Post by Ray O

Post by Pete B
Dear Lexus Experts -
Have just started having some intermittent problems with my 2000 ES300
(58,000 miles, Northeast USA) turning over OK on turning the key, but not
"catching". The car immediately stalls out, and it sometimes takes a number
of tries and depressing the gas pedal until it idles on its own. As usual,
once it's running, it's smooth, quiet, and performs as I would expect.
Any
ideas on what might be failing?
Thanx,
Pete

Several things can cause the symptoms you are describing. Check the air
filter to make sure it is not clogged and the passage out of the air filter
does not have any debris accumulated in it.
The cold start enrichment system may not be working. Check to make sure the
coolant temperature sensors are hooked up. If you have a volt meter, check
for increasing voltage out of the sensors as the coolant warms up.
Check the MAF sensor to make sure there is no gunk accumulated on the wire
inside the tube that sticks out into the air stream.
If all that stuff checks out, have the fuel pressure checked to make sure
fuel pressure is not dropping while the vehicle is parked. If it is, check
the fuel pressure regulator.
--
Ray O
(correct punctuation to reply)

[Ray O]

Post by Pete B
Thanx Ray.

You're welcome!

[toyomoho]

Also check/clean IAC valve.