87 Aries 2.5L - Sky High Idle - Help!
Mark Chadwick
Hello
Anyone have any past experiences with a very high idle problem on a 2.5L
TB injected and has about 160k km on it..
There does not appear to be any vacuum leaks. The Throttle Position Sensor
and the MAP Sensor have been recently replaced. No Error codes stored in
the computer (as per the count the light flashes).
I was going to pull off the Idle Speed Motor (something stuck in it ?) and
check/replace the throttle body gasket at the same time as a next step.
One last question: Anyone else have model eat brake master cylinders?
the car is 10 years old and I am about to put the 4th new one in!
Anyone had this problem? or any other ideas would be appreciated.
Thanks
Mark Chadwick
-Bodnar,B.L.
In article <01bc456c$569ac7a0$5802...@mchadwick.ica.net>,
Mark Chadwick <mcha...@ica.net> wrote:
>Hello
>
>Anyone have any past experiences with a very high idle problem on a 2.5L
>TB injected and has about 160k km on it..
>
>There does not appear to be any vacuum leaks. The Throttle Position Sensor
>and the MAP Sensor have been recently replaced. No Error codes stored in
>the computer (as per the count the light flashes).
>
>I was going to pull off the Idle Speed Motor (something stuck in it ?) and
>check/replace the throttle body gasket at the same time as a next step.
Does this problem occur when the engine's hot or when it's cold (or, does it
matter?). High idle speed in a speed-density controlled engine (like yours)
is almost always indicative of an air leak (MAP sensor sees high pressure,
computer interprets this as a power demand and increases injector pulse
width). Simply because the on-board diagnostics haven't caught a problem does
not mean that there's no problem.
Another thing to look for is corroded connections to the engine coolant
temperature sensor. If the powertrain control module "thinks" the engine's
cold, it will increase engine rpm in order to warm up the engine.
These are the MAJOR things I'd look at. If these are discounted, then I'd
look at battery voltage sensing (if the computer "thinks" the voltage is too
low, it'll increase the injector pulse width) and fuel pressure.
Incidently, do you have black smoke on startup or when the engine's cold?
>
>One last question: Anyone else have model eat brake master cylinders?
>the car is 10 years old and I am about to put the 4th new one in!
>
>Anyone had this problem? or any other ideas would be appreciated.
>
There's no reason why this car should "eat" master cylinders UNLESS the piston
travel is incorrectly set. These are anodized aluminum cylinders and
therefore don't produce the damaging rust particles which damage the seals.
A properly installed AND REBUILT master cylinder should outlast the car.
>Thanks
>
>Mark Chadwick
>
Cordially,
Bohdan Bodnar
bbo...@lucent.com
Mark Chadwick
Hi Bohdan
Thanks for the reply. I have included some more info after your
questions. I really appreciate the help.
-Bodnar,B.L. <boh...@ihgp4.ih.lucent.com> wrote in article
<5iio2s$p...@ssbunews.ih.lucent.com>...
> In article <01bc456c$569ac7a0$5802...@mchadwick.ica.net>,
> Mark Chadwick <mcha...@ica.net> wrote:
> >Hello
> >
> >Anyone have any past experiences with a very high idle problem on a 2.5L
> >TB injected and has about 160k km on it..
> >
> >There does not appear to be any vacuum leaks. The Throttle Position
Sensor
> >and the MAP Sensor have been recently replaced. No Error codes stored
in
> >the computer (as per the count the light flashes).
> >
> >I was going to pull off the Idle Speed Motor (something stuck in it ?)
and
> >check/replace the throttle body gasket at the same time as a next step.
>
> Does this problem occur when the engine's hot or when it's cold (or, does
it
> matter?). High idle speed in a speed-density controlled engine (like
yours)
> is almost always indicative of an air leak (MAP sensor sees high
pressure,
> computer interprets this as a power demand and increases injector pulse
> width). Simply because the on-board diagnostics haven't caught a problem
does
> not mean that there's no problem.
I have been over all the vacuum lines listed on the routing diagram under
the hood looking for leaks. I have disconnected and plugged them one at a
time and observed the results. There has been almost no effect on running
(except when you disconnect the one going to the MAP sensor!). The problem
seems to exist regardless of engine temp. From stone cold it revs up and
starts to come down. If it is really cold < -5 to -10C is goes go down
low up ( but is almost stumbling) after less than a minute it will rise and
stay that way regardless. If the air temp is above 0 it reves up and only
drops slightly.
The vacuum leak idea is why I was going to pull off the throttle body and
replace the gasket. It looks like it is in one piece, but ......
Since the engine will slow down to a low (and really rough) idle when I
disconnect the vacuum to the MAP sensor ( and plug the line of course),
does this indicate the AIS motor is working properly?
> Another thing to look for is corroded connections to the engine coolant
> temperature sensor. If the powertrain control module "thinks" the
engine's
> cold, it will increase engine rpm in order to warm up the engine.
I have tried disconnecting the temp sensor and the Power Loss light goes
on - engine revs very high and then comes down to a very low stumbling
idle. Any touch on the gas pedal sends it up very high and slowly
declines. The pins on this connector look shiney and clean, but I will try
some contact cleaner on them. Thisa will produce the error code on the
computer.
>
> These are the MAJOR things I'd look at. If these are discounted, then
I'd
> look at battery voltage sensing (if the computer "thinks" the voltage is
too
> low, it'll increase the injector pulse width) and fuel pressure.
>
> Incidently, do you have black smoke on startup or when the engine's cold?
>
No black smoke at all. Is there a simple way to test the voltage sense
circuit? without the Chrysler test box?
> >
> >One last question: Anyone else have model eat brake master cylinders?
> >the car is 10 years old and I am about to put the 4th new one in!
> >
> >Anyone had this problem? or any other ideas would be appreciated.
> >
>
> There's no reason why this car should "eat" master cylinders UNLESS the
piston
> travel is incorrectly set. These are anodized aluminum cylinders and
> therefore don't produce the damaging rust particles which damage the
seals.
> A properly installed AND REBUILT master cylinder should outlast the car.
The present master cylinder housing is steel (its coated in rust) and is a
Wagner unit. I don't know if it has an aluminum sleeve. The installation
instruction did not mention the travel is adjustable, but I guess that
would make sense. The original unit in this car only lasted about 3 years
(if I remember correctly it had a plastic housing. I know the travel on
the clutch master cylinder on my truck is adustable, but I didn't realize
it was adjustable on these brakes. I will check the Mitchel manual for
this proceedure.
Thanks again, for your help!
Regards
Mark Chadwick
tra...@acsu.buffalo.edu
On 10 Apr 1997, Mark Chadwick wrote:
> Hello
>
> Anyone have any past experiences with a very high idle problem on a 2.5L
> TB injected and has about 160k km on it..
>
> There does not appear to be any vacuum leaks. The Throttle Position Sensor
> and the MAP Sensor have been recently replaced. No Error codes stored in
> the computer (as per the count the light flashes).
>
> I was going to pull off the Idle Speed Motor (something stuck in it ?) and
> check/replace the throttle body gasket at the same time as a next step.
>
I am having a similar problem with my 88 Aries 2.2l. This only happens
sometimes, particularly when the car has taken out of gear and put in
park, usually for a few minutes. However, this happened to me this
morning when i was in the middle of an intersection and it was happening
so bad the brakes were squealing and when i let the brakes off the car
took off quiker than normal without giving it gas. Does your problem
happen sometimes or always? Like i say, mine is only sometimes, so i
don't know if it is the same problem.
Daniel Tranter
88 Dodge Aries 2.2L
Mark Chadwick
Hi Daniel
I don't drive this car on a regular basis - it's my wife's car. It appears
to have started over a period of time. You would be sitting at a stoplight
and it would rev up. If you put it in neutral and reved it up yourself it
would usuallly come back down. Right now it's up and it stays there.
Regards
Mark
> >
snip
Jeremy Warnock
In article <01bc4a1d$f5b7c620$4602...@mchadwick.ica.net>,
mcha...@ica.net says...
> Hi Daniel
>
> I don't drive this car on a regular basis - it's my wife's car. It appears
> to have started over a period of time. You would be sitting at a stoplight
> and it would rev up. If you put it in neutral and reved it up yourself it
> would usuallly come back down. Right now it's up and it stays there.
>
> Regards
>
> Mark
I had a similiar problem with my 2.5L and it ended up being a faulty
throttle position sensor. Along with the high idle speeds and I also
noticed some slight surging at cruising speeds. All of the problems
appeared to happen randomly but the high idle speeds here worst when I
came of the highway.
Jeremy Warnock
tra...@acsu.buffalo.edu
On Sat, 12 Apr 1997, Daniel H Tranter wrote:
> On 10 Apr 1997, Mark Chadwick wrote:
>
> > Hello
> >
> > Anyone have any past experiences with a very high idle problem on a 2.5L
> > TB injected and has about 160k km on it..
> >
> > There does not appear to be any vacuum leaks. The Throttle Position Sensor
> > and the MAP Sensor have been recently replaced. No Error codes stored in
> > the computer (as per the count the light flashes).
> >
> > I was going to pull off the Idle Speed Motor (something stuck in it ?) and
> > check/replace the throttle body gasket at the same time as a next step.
>
> >
> I am having a similar problem with my 88 Aries 2.2l. This only happens
> sometimes, particularly when the car has taken out of gear and put in
> park, usually for a few minutes. However, this happened to me this
> morning when i was in the middle of an intersection and it was happening
> so bad the brakes were squealing and when i let the brakes off the car
> took off quiker than normal without giving it gas. Does your problem
> happen sometimes or always? Like i say, mine is only sometimes, so i
> don't know if it is the same problem.
>
> Daniel Tranter
> 88 Dodge Aries 2.2L
>
I have solved my high idle problem. I sprayed some WD40 into the
throttle body and it;s fixed. Obviously, the throttle must have been
sticking open too much when the gas was eased off and the car should have
been decelerating. Try doing this to yours (in case you don't know, the
throttle body is next to the air filter under the plastic cover)
Daniel Tranter
88 Aries 2.2l >