2001 Corolla hesitation/power/ping problem

Greetings,
My girlfriend has a 2001 Corolla with 67k miles on it. The problem is
this; When first started, it starts fine, but if you put on the AC
right away, it stalls. Accelerating after coming to a stop causes the
car to nearly stall out (power dies for a second or two, but recovers
somewhat). Acceleration at most speeds is delayed, but once the delay
is over the car has normal power. The problem seems to get worse during
damp weather. The car also pings except under hard acceleration. It
also seemed to be worse during the winter (we live in cool Vermont).

So far, we've replaced the plugs, air filter, and pcv valve. We have
not yet seen a check engine light come on, and we've had someone do an
OBDII read on it. Does anyone know any tests that i could perform to
diagnose this? I have a full garage with a lift, so I can do everything
myself. Thanks much... Derek

> wrote in message
ups.com...
> Greetings,
> My girlfriend has a 2001 Corolla with 67k miles on it. The problem is
> this; When first started, it starts fine, but if you put on the AC
> right away, it stalls. Accelerating after coming to a stop causes the
> car to nearly stall out (power dies for a second or two, but recovers
> somewhat). Acceleration at most speeds is delayed, but once the delay
> is over the car has normal power. The problem seems to get worse during
> damp weather. The car also pings except under hard acceleration. It
> also seemed to be worse during the winter (we live in cool Vermont).
>
> So far, we've replaced the plugs, air filter, and pcv valve. We have
> not yet seen a check engine light come on, and we've had someone do an
> OBDII read on it. Does anyone know any tests that i could perform to
> diagnose this? I have a full garage with a lift, so I can do everything
> myself. Thanks much... Derek
>

Check engine vacuum at idle and high engine RPM, look for 14-16 inHg at
idle.

Check for cracks in the intake hose between the air flow meter and intake
manifold

If you did not use OEM spark plugs, use them.

Check ignition timing.
--
Ray O
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