93 Corolla - gas pedal "sticky"

Except that it isn't literally "sticky". I cleaned and lubed the
throttle cable, and it's perfectly OK as long as the engine is off.

With the engine running, when you're at a stop light the pedal gets
"sticky" and requires a relatively hard push to get moving again.

Feels like you have to overcome some pressure [whether it's vacuum or
positive pressure I don't know] that builds up while the engine is
idling, and as soon as you have bled this off, the pedal behaves
normally.

What could this be? Vacuum leak? Problem in the throttle body itself?

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1159138739.877590.67930@m73g2000cwd.googlegroups.com...[color=blue]
> Except that it isn't literally "sticky". I cleaned and lubed the
> throttle cable, and it's perfectly OK as long as the engine is off.
>
> With the engine running, when you're at a stop light the pedal gets
> "sticky" and requires a relatively hard push to get moving again.
>
> Feels like you have to overcome some pressure [whether it's vacuum or
> positive pressure I don't know] that builds up while the engine is
> idling, and as soon as you have bled this off, the pedal behaves
> normally.
>
> What could this be? Vacuum leak? Problem in the throttle body itself?
>[/color]

Most likely, it is a buildup inside the throttle body, causing the throttle
plate to stick to the inside of the throttle body. Get a can of aerosol
carburetor/EFI cleaner at an auto parts store. With the engine off, follow
the plastic snorkel from the air cleaner to the throttle body and remove the
snorkel from the throttle body. When you look into the throttle body, you
will see a round plate that pivots in the middle of the plate. Spray the
plate with the carb cleaner and wipe the plate and the runoff with a paper
towel. Turn the bellcrank that is attached to the throttle cable to open
the throttle plate and clean up the edges of the plate, pivot points, and
the far side of the plate, wiping up as much of the runoff as you can. Put
everything back together and start the car. It will smoke like crazy until
everything is burned off.
--

Ray O
(correct punctuation to reply)

Hi,
[color=blue][color=green]
> > With the engine running, when you're at a stop light the pedal gets
> > "sticky" and requires a relatively hard push to get moving again.[/color]
>
> Most likely, it is a buildup inside the throttle body, causing the throttle
> plate to stick to the inside of the throttle body. Get a can of aerosol[/color]

I've got plenty of carb cleaner (I own a '65 Scout :) so I'll try that
tonight, thanks. But this symptom only happens when the engine is
running... still think it's a gummy throttle plate?

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1159182577.778980.304720@k70g2000cwa.googlegroups.com...[color=blue]
> Hi,
>[color=green][color=darkred]
>> > With the engine running, when you're at a stop light the pedal gets
>> > "sticky" and requires a relatively hard push to get moving again.[/color]
>>
>> Most likely, it is a buildup inside the throttle body, causing the
>> throttle
>> plate to stick to the inside of the throttle body. Get a can of aerosol[/color]
>
> I've got plenty of carb cleaner (I own a '65 Scout :) so I'll try that
> tonight, thanks. But this symptom only happens when the engine is
> running... still think it's a gummy throttle plate?
>[/color]

Yup. When the engine is warmed up, the gum gets gummier than when it is
cold.
--

Ray O
(correct punctuation to reply)

"Ray O" <rokigawaATtristarassociatesDOTcom> wrote in message news:ee1cc$4517dc09$44a4a10d$13485@msgid.meganewsservers.com...[color=blue]
>
> "larwe" <zwsdotcom@gmail.com> wrote in message news:1159182577.778980.304720@k70g2000cwa.googlegroups.com...[color=green]
>> Hi,
>>[color=darkred]
>>> > With the engine running, when you're at a stop light the pedal gets
>>> > "sticky" and requires a relatively hard push to get moving again.
>>>
>>> Most likely, it is a buildup inside the throttle body, causing the throttle
>>> plate to stick to the inside of the throttle body. Get a can of aerosol[/color]
>>
>> I've got plenty of carb cleaner (I own a '65 Scout :) so I'll try that
>> tonight, thanks. But this symptom only happens when the engine is
>> running... still think it's a gummy throttle plate?
>>[/color]
>
> Yup. When the engine is warmed up, the gum gets gummier than when it is cold.
> --
>
> Ray O
> (correct punctuation to reply)[/color]


Yep, yep... Imagine your foot stuck in the mud! Not to mention throttle response.

Dan

Ray O wrote:
[color=blue][color=green]
> > I've got plenty of carb cleaner (I own a '65 Scout :) so I'll try that
> > tonight, thanks. But this symptom only happens when the engine is
> > running... still think it's a gummy throttle plate?
> >[/color]
>
> Yup. When the engine is warmed up, the gum gets gummier than when it is
> cold.[/color]

Perhaps I should have been more specific... With the engine hot but not
running, the problem does not occur. With the engine running, either
hot or cold, the problem occurs within 30 seconds of taking one's foot
off the gas.

Hence my inference that this is some kind of vacuum-related issue. But
I'll try the cleaning anyway, hopefully that is it!

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1159204168.718285.10690@m7g2000cwm.googlegroups.com...[color=blue]
>
> Ray O wrote:
>[color=green][color=darkred]
>> > I've got plenty of carb cleaner (I own a '65 Scout :) so I'll try that
>> > tonight, thanks. But this symptom only happens when the engine is
>> > running... still think it's a gummy throttle plate?
>> >[/color]
>>
>> Yup. When the engine is warmed up, the gum gets gummier than when it is
>> cold.[/color]
>
> Perhaps I should have been more specific... With the engine hot but not
> running, the problem does not occur. With the engine running, either
> hot or cold, the problem occurs within 30 seconds of taking one's foot
> off the gas.
>
> Hence my inference that this is some kind of vacuum-related issue. But
> I'll try the cleaning anyway, hopefully that is it!
>[/color]

Clean the throttle body thoroughly as I described, including where the pivot
pin penetrates the throttle body. I have never heard of any instances where
this procedure did not work for a throttle pedal that sticks in the closed
position. Let us know if the cleaning works or does not work.
--

Ray O
(correct punctuation to reply)

Ray O wrote:
[color=blue][color=green]
> > Perhaps I should have been more specific... With the engine hot but not
> > running, the problem does not occur. With the engine running, either
> > hot or cold, the problem occurs within 30 seconds of taking one's foot[/color]
>
> Clean the throttle body thoroughly as I described, including where the pivot
> pin penetrates the throttle body. I have never heard of any instances where[/color]

OK, I stand corrected. Cleaning the throttle (which has probably not
been opened in the last 13 years...) used almost an entire can of carb
cleaner but totally fixed the problem. The vehicle also starts a little
easier. Now I feel a lot better about my wife driving this beast in
stop-n-go traffic (NYC). Thanks a lot!

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1159312806.944100.268550@k70g2000cwa.googlegroups.com...[color=blue]
>
> Ray O wrote:
>[color=green][color=darkred]
>> > Perhaps I should have been more specific... With the engine hot but not
>> > running, the problem does not occur. With the engine running, either
>> > hot or cold, the problem occurs within 30 seconds of taking one's foot[/color]
>>
>> Clean the throttle body thoroughly as I described, including where the
>> pivot
>> pin penetrates the throttle body. I have never heard of any instances
>> where[/color]
>
> OK, I stand corrected. Cleaning the throttle (which has probably not
> been opened in the last 13 years...) used almost an entire can of carb
> cleaner but totally fixed the problem. The vehicle also starts a little
> easier. Now I feel a lot better about my wife driving this beast in
> stop-n-go traffic (NYC). Thanks a lot!
>[/color]

I do try to avoid giving bad advice ;-) You're welcome and thank you for
posting your results!
--

Ray O
(correct punctuation to reply)