More on the maf questions.

I have just had a quick read some of the info on cleaning the MAF sensor and
some of it's symptoms, and one of the things mentioned was auto gearbox
performance issues.
I am thinking that this may be the cause of a coupleof gearbox problem I
have with a '98 V6 Camry, and I am wondering if anybody can confirm or deny
whether this is the case

The gearbox performs o.k. but when running on the highway at say 80 to 90
K.P.H. (50 to 55 M.P.H.) on a light throttle, just on that point of closing
the throttle, (this is a bit hard to describe as "you had to be there"!) the
torque converter lockup "Hunts" it makes it a bit hard to sit behind that
slower car smoothly. At any other speed it seems fine and on cruise control
it seems fine

The other prob is that when it is cold, it takes a little while before it
will change into top gear, sometimes a little extra throttle "coaxes" it
into top but most times it wakes up after a couple of hundred metres and
shifts fine for the rest of the trip. This only seems to occur from stone
cold, the rest of the day it is fine.
I believe there is a temp. sensor in the box and maybe it is just this that
is a bit slow.
Any comments.
Thanks.
Tim.

"T.J.& L.K. Dunster" <dunstert@bigpond.net.au> wrote in message
news:IYx5g.20549$vy1.15041@news-server.bigpond.net.au...[color=blue]
>I have just had a quick read some of the info on cleaning the MAF sensor
>and
> some of it's symptoms, and one of the things mentioned was auto gearbox
> performance issues.
> I am thinking that this may be the cause of a coupleof gearbox problem I
> have with a '98 V6 Camry, and I am wondering if anybody can confirm or
> deny
> whether this is the case
>
> The gearbox performs o.k. but when running on the highway at say 80 to 90
> K.P.H. (50 to 55 M.P.H.) on a light throttle, just on that point of
> closing
> the throttle, (this is a bit hard to describe as "you had to be there"!)
> the
> torque converter lockup "Hunts" it makes it a bit hard to sit behind that
> slower car smoothly. At any other speed it seems fine and on cruise
> control
> it seems fine[/color]

I believe that your transmission is controlled electronically, so the
hunting that you're experiencing is difficult to get rid of. When I used to
work with customers who complained of this, I noticed that drivers become
fixated on the condition and adjust their driving so that it keeps
reocurring. When I went for test drives with the customers, the condition
did not appear but when the customer drove, the condition re-appeared. I
most cases, the condition can be eliminated by driving a little differently
or pushing the OD off button.
[color=blue]
>
> The other prob is that when it is cold, it takes a little while before it
> will change into top gear, sometimes a little extra throttle "coaxes" it
> into top but most times it wakes up after a couple of hundred metres and
> shifts fine for the rest of the trip. This only seems to occur from stone
> cold, the rest of the day it is fine.
> I believe there is a temp. sensor in the box and maybe it is just this
> that
> is a bit slow.
> Any comments.
> Thanks.
> Tim.
>[/color]
The system is designed to delay shifting into top gear until the engine
coolant is warmed up. This is normal operation.
--

Ray O
(correct punctuation to reply)

Fair enough, you are the second person to suggest switching it out of
overdrive and I will try that next time I am on the highway and the driving
conditions re-occur.
As I stated, I have driven a couple of other V6 Camrys of about the same
age, mileage and condition and have deliberately tried to recreate the
problem in them with no success.
I have never had the same problem with other similar makes of cars, so I
suspect that there is a condition in my car that is out of the ordinary.
I do not go out of my way to make the car do this but the condition occurs
at a speed that I would normally not cruise at and tends to be in a fast
traffic situation were I am either gaining on the vehicle in front or
slowing down and inconveniencing the vehicle behind.
I also do not discount for the fact that it may be "Just me" and I will try
and alter my driving to suit.
Anyway I will certainly try it out of overdrive and see if that improves the
situation.
Thanks for the info and advise.
Tim.



"Ray O" <rokigawa@tristarassociatesDOTcomn> wrote in message
news:a1f18$4456efbe$180fead6$13628@msgid.meganewsservers.com...[color=blue]
>
> "T.J.& L.K. Dunster" <dunstert@bigpond.net.au> wrote in message
> news:IYx5g.20549$vy1.15041@news-server.bigpond.net.au...[color=green]
> >I have just had a quick read some of the info on cleaning the MAF sensor
> >and
> > some of it's symptoms, and one of the things mentioned was auto gearbox
> > performance issues.
> > I am thinking that this may be the cause of a coupleof gearbox problem I
> > have with a '98 V6 Camry, and I am wondering if anybody can confirm or
> > deny
> > whether this is the case
> >
> > The gearbox performs o.k. but when running on the highway at say 80 to[/color][/color]
90[color=blue][color=green]
> > K.P.H. (50 to 55 M.P.H.) on a light throttle, just on that point of
> > closing
> > the throttle, (this is a bit hard to describe as "you had to be there"!)
> > the
> > torque converter lockup "Hunts" it makes it a bit hard to sit behind[/color][/color]
that[color=blue][color=green]
> > slower car smoothly. At any other speed it seems fine and on cruise
> > control
> > it seems fine[/color]
>
> I believe that your transmission is controlled electronically, so the
> hunting that you're experiencing is difficult to get rid of. When I used[/color]
to[color=blue]
> work with customers who complained of this, I noticed that drivers become
> fixated on the condition and adjust their driving so that it keeps
> reocurring. When I went for test drives with the customers, the condition
> did not appear but when the customer drove, the condition re-appeared. I
> most cases, the condition can be eliminated by driving a little[/color]
differently[color=blue]
> or pushing the OD off button.
>[color=green]
> >
> > The other prob is that when it is cold, it takes a little while before[/color][/color]
it[color=blue][color=green]
> > will change into top gear, sometimes a little extra throttle "coaxes" it
> > into top but most times it wakes up after a couple of hundred metres and
> > shifts fine for the rest of the trip. This only seems to occur from[/color][/color]
stone[color=blue][color=green]
> > cold, the rest of the day it is fine.
> > I believe there is a temp. sensor in the box and maybe it is just this
> > that
> > is a bit slow.
> > Any comments.
> > Thanks.
> > Tim.
> >[/color]
> The system is designed to delay shifting into top gear until the engine
> coolant is warmed up. This is normal operation.
> --
>
> Ray O
> (correct punctuation to reply)
>
>[/color]

T.J. Dunster wrote:[color=blue]
> Fair enough, you are the second person to suggest switching it out of
> overdrive and I will try that next time I am on the highway and the driving
> conditions re-occur.
>snip[/color]

I have a '98 Sienna. In certain traffic situations I turn "OD off" to
avoid transmission "gear hunting" (which I think is more torque
converter lockup than gear hunting but why split hairs). Like you, I
find this condition in certain situations (irregular
slowing/accelerating in heavy traffic) only.

I also own two manual transmission vehicles. Now there's some fun in
heavy traffic!

"T.J. Dunster" <dunstert@bigpond.net.au> wrote in message
news:tBF5g.20969$vy1.20219@news-server.bigpond.net.au...[color=blue]
> Fair enough, you are the second person to suggest switching it out of
> overdrive and I will try that next time I am on the highway and the
> driving
> conditions re-occur.
> As I stated, I have driven a couple of other V6 Camrys of about the same
> age, mileage and condition and have deliberately tried to recreate the
> problem in them with no success.
> I have never had the same problem with other similar makes of cars, so I
> suspect that there is a condition in my car that is out of the ordinary.
> I do not go out of my way to make the car do this but the condition occurs
> at a speed that I would normally not cruise at and tends to be in a fast
> traffic situation were I am either gaining on the vehicle in front or
> slowing down and inconveniencing the vehicle behind.
> I also do not discount for the fact that it may be "Just me" and I will
> try
> and alter my driving to suit.
> Anyway I will certainly try it out of overdrive and see if that improves
> the
> situation.
> Thanks for the info and advise.
> Tim.
>[/color]

if you still feel that there is something wrong with the transmission, a
Toyota dealer can hook up a scan tool (more sophisticated than a regular OD
II scan tool) and monitor what is actually going on with the transmission.
they will be able to tell you what gear it is in, whether the torque
converter is locked or unlocked, etc and you will have hard data to compare
with factory specifications.
--

Ray O
(correct punctuation to reply)