Car stuck on Full throttle????

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Ben Martin - 12 Jun 2006 21:28 GMT

My car "redlines" when I start it.

It is like the throttle is stuck.

In a previous post, I suggested something to do with th transmission was on
the fritz. But that is most likely incorrect. After futher consideration
it seems that my throttle is somehow stuck on wide open.

Any ideas???
Thanks in advance.

- Ben

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admin - 12 Jun 2006 22:05 GMT

> My car "redlines" when I start it.
>
[quoted text clipped - 8 lines]
>
> - Ben

Have you even opened the hood and looked? You have a 17-18 year old car.

It's entirely possible the throttle cable has worn to the point of
sticking. You need to track down the cable and see if the end looks
frayed. If what I'm saying makes no sense to you - call for a tow and
have it taken to a shop (dealer or independent.) Running the engine at
redline for very long is a sure-fire way to destroy the engine.

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Ben Martin - 12 Jun 2006 23:16 GMT

To answer your question - I been looking under the hood for the last few
months, about every other day for one problem or another. The car has
230,000 miles. In the past few months I have - with some help - replaced
the:

Mass Airflow Sensor

Starter

Air Intake Manifold Gasket

The information I have received from this Newsgroup has been very helpful in
most cases

Where my current problem is concerned, I have not yet noticed anything wierd
about the throttle cable.

But I am reading the Bentley manual and find myself wondering if the "Idle
and Full Throttle Switch" could malfunction and cause my engine to run at
full speed (redline).

Or maybe there are other components, when failed, that could cause an
engine to fun at full speed.

All responses are appreciated.

Thanks in advance.

- Ben

> > My car "redlines" when I start it.
> >
[quoted text clipped - 16 lines]
> have it taken to a shop (dealer or independent.) Running the engine at
> redline for very long is a sure-fire way to destroy the engine.

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David Matkin - 12 Jun 2006 23:29 GMT

> To answer your question - I been looking under the hood for the last few
> months, about every other day for one problem or another. The car has
[quoted text clipped - 47 lines]
>> have it taken to a shop (dealer or independent.) Running the engine at
>> redline for very long is a sure-fire way to destroy the engine.

Your car can only possibly redline if the throttle is open and that can
only possibly be produced by the throttle cable. There are no other
actualtors / stepomotors in the car that can do this. It should be a
relatively cheap fix - I hope!

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Floyd Rogers - 12 Jun 2006 23:46 GMT

> Ben Martin wrote:
>> Where my current problem is concerned, I have not yet noticed anything
[quoted text clipped - 8 lines]
>> Or maybe there are other components, when failed, that could cause an
>> engine to fun at full speed.

> Your car can only possibly redline if the throttle is open and that can
> only possibly be produced by the throttle cable. There are no other
> actualtors / stepomotors in the car that can do this. It should be a
> relatively cheap fix - I hope!

It would be way easier if you guys would use one (bottom) posting style.

If your car has cruise control, it could be the CC motor/cable.

The other thing I haven't seen mentioned is crankshaft position sensor.
Don't know if the M20 had one... Wouldn't think that that would
cause over-rev (usually start/run problems.)

FloydR

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admin - 13 Jun 2006 14:29 GMT

> It would be way easier if you guys would use one (bottom) posting style.

I don't believe in top or bottom posting style. I believe in adding
comments where they might be understood.

> If your car has cruise control, it could be the CC motor/cable.

Could, but I've never heard of one actuating itself. I think he has to
get to some elementary checks - like is the throttle body stuck wide
open? Is so - why? He mentioned he's replaced the intake manifold
gasket(s) - so he should be familiar with the area, and there is always
the chance he messed something up doing that job.

> The other thing I haven't seen mentioned is crankshaft position sensor.
> Don't know if the M20 had one... Wouldn't think that that would
> cause over-rev (usually start/run problems.)

CPS has nothing to do with an over-rev condition. Nothing. Guarantee.

> FloydR

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Rex B - 13 Jun 2006 15:29 GMT

> I don't believe in top or bottom posting style. I believe in adding
> comments where they might be understood.

I agree. If I am replying to a lengthy post that should not be snipped,
I'll top-post rather than require the reader to scroll down past a
message he has probably read earlier.

OTOH, if I'm reply to just a 2-line portion snipped from a larger
message, I'll bottom-post.

The whole point us readability.

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Dean Dark - 13 Jun 2006 22:56 GMT

>> I don't believe in top or bottom posting style. I believe in adding
>> comments where they might be understood.
>
>I agree. If I am replying to a lengthy post that should not be snipped,
>I'll top-post rather than require the reader to scroll down past a
>message he has probably read earlier.

"...should not be snipped..."

Well, there's your problem. It's about *editing* for content, not
wholesale *snipping*.

A lengthy post really needs to be edited down to the essential part to
which you are responding. Remember, we read the original post; we
don't need to read the whole damned thing again. The trouble is, it
takes a little time and thought.

Signature

Dan.

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Jeff Strickland - 14 Jun 2006 05:15 GMT

What sucks is that some people witll top post.

>> I don't believe in top or bottom posting style. I believe in adding
>> comments where they might be understood.
>
> I agree. If I am replying to a lengthy post that should not be snipped,
> I'll top-post rather than require the reader to scroll down past a message
> he has probably read earlier.

Some will add in the middle where it makes more sense.

> OTOH, if I'm reply to just a 2-line portion snipped from a larger message,
> I'll bottom-post.

And some will post on the bottom.

> The whole point us readability.

I like to post where it makes sense. This is at the top, in the middle, or
on the bottom. It always is determine by what has been said before me, and
how. Readability is key.

Floyd was addressing the point that one guy posted on the bottom, and the
next reply was a top post. This gets tedious.

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Jeff Strickland - 14 Jun 2006 05:12 GMT

>> It would be way easier if you guys would use one (bottom) posting style.
>
[quoted text clipped - 8 lines]
> should be familiar with the area, and there is always the chance he messed
> something up doing that job.

I'm with you, admin. I don't think the Cruise can cause this, and I think
there are some elementry checks for stuff that is binding/bound up. As for
missing something on the earlier repair, perhaps the throttle return spring
is on backwards.

>> The other thing I haven't seen mentioned is crankshaft position sensor.
>> Don't know if the M20 had one... Wouldn't think that that would
[quoted text clipped - 3 lines]
>
>> FloydR

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Psycho - 13 Jun 2006 20:39 GMT

>It would be way easier if you guys would use one (bottom) posting style.

Other than personal preference, why? Please don't start the debate,
just cracking a funny..

>If your car has cruise control, it could be the CC motor/cable.
>
[quoted text clipped - 3 lines]
>
>FloydR

The crank position sensor is irrelevant in this matter as is the
cruise control. The throttle is being held open probably by a frayed
cable or just worn parts. Grab the linkage and work it back and forth.
If it doesn't move from one extreme to the other without sticking,
you've found the problem.

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Jeff Strickland - 14 Jun 2006 05:19 GMT

>>It would be way easier if you guys would use one (bottom) posting style.
>
[quoted text clipped - 12 lines]
> cruise control. The throttle is being held open probably by a frayed
> cable or just worn parts.

DING DING DING We have a winner!
The throttle is being held open, and my guess is the return spring (since
the OP confessed to replacing the intake manifold recently).

Grab the linkage and work it back and forth.

> If it doesn't move from one extreme to the other without sticking,
> you've found the problem.

Excellent test. It will not only help isolate the problem, it will cause him
to look closely at the mechanical interaction of parts that are there. I'd
also suggest working the throttle pedal by hand.

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Dan Buchan - 12 Jun 2006 23:40 GMT

> But I am reading the Bentley manual and find myself wondering if the "Idle
> and Full Throttle Switch" could malfunction and cause my engine to run at
> full speed (redline).

No, that's not possible. To run at that speed it needs air, which is
provided by the throttle valve being physically open. Sensors and switches
can alter the amount of fuel but not that, not on an older car anyway.

You need to find where the accelerator cable goes to the throttle and see
what is going on. You can physically move the throttle valve by hand to
achieve the same effect as pressing the pedal. Just follow the air intake
through to the throttle body and find where the cable goes in. Should be
very easy to see.

The cable could be stuck, a return spring could be broken, and although it
sounds daft it's not uncommon for the pedal to get wedged down against the
floor mat.

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