High Idle 4500 RPM

now factor in the job the i.a.c does

Matt Whiting wrote:

> maxpower wrote:
>
> > it is the same thing regardless if it is the throttle blade opening or a
> > huge vacuum leak, the MAP sensor determines how much fuel to give it, not
> > the throttle blade. if you disconnected the TPS sensor and opened the
> > throttle blade, the map sensor would compensate for it, thus causing a high
> > RPM The throttle blade does not have anything to do with giving more gas, a
> > carburator would but not this vehicle
>
> Last I knew, the TPS sensor was also factored into the fuel map for ECM
> controlled vehicles. Maybe Chrysler was really stupid with their ECM,
> but I doubt it. If the throttle is closed as indicated by the TPS, then
> I'd be really surprised if the MAP input alone would be enough to
> command fuel be added. If that is the case, then the TPS is completely
> unnecessary.
>
> Matt

hmm could that neil nelson sure types like him

aarcuda69062 wrote:

> In article >,
> Matt Whiting > wrote:
>
> > maxpower wrote:
> >
> > > Your right it isnt that nessassary. more of a reference point of open and
> > > closed throtlle, u can unhook the tps sensor and the engine will run, it
> > > will give a hesitation on take off but will run because the MAP sensor
> > > determines load and how much fuel to deliver
> >
> > I don't think Chrysler publishes its ECM algorithms, but I've be very
> > surprised if the TPS is used only to sense closed and WOT.
>
> ~Excluding transmission/transaxle functions~
> Rate of change in order to increase the injector pulse width when
> the throttle is opened.
> Idle air control valve diagnostics (fault sensing)
> The TPS is the least important of all the input sensors, its
> biggest effect on fuel delivery is when the PCM is receiving a
> changing voltage from it indicating throttle movement.
>
> > If that were the case, they would use two cheap switches rather than a relatively
> > expensive rheostat sensor.
>
> Some manufactures have been known to do this.
>
> > I'd also be very surprised if they don't
> > make a check for closed throttle when the MAP is indicating low pressure
>
> Closed throttle low MAP pressure is a heavy decel, which is a
> whole different situation from the potential mass vacuum leak
> being discussed.
> A vacuum leak that can/does add hundreds of RPM to idle speed
> -raises- manifold absolute pressure, raising manifold pressure is
> usually responded to by the PCM by as an increased injector pulse
> width.
>
> > and thus calling for more fuel and not rev the engine wildly with a
> > closed throttle. Maybe the Chrysler engineers aren't that smart, but
> > I'm betting they are.
>
> Some things are beyond the limits of control of the system.
>
> > Have you ever seen a Chrysler engine have a vacuum leak that made it run
> > 4,500 RPM with the throttle closed?
>
> You've got a minivan or two at your disposal...
> Hook up your scanner, pull the PCV or brake booster hose off,
> start the engine and report back with the results, i.e., RPM
> changes, MAP changes, pulse width changes.
> You may not see 4500 RPM exactly, but you will experience the
> causes and effect.

hmm could that neil nelson sure types like him

aarcuda69062 wrote:

> In article >,
> Matt Whiting > wrote:
>
> > maxpower wrote:
> >
> > > Your right it isnt that nessassary. more of a reference point of open and
> > > closed throtlle, u can unhook the tps sensor and the engine will run, it
> > > will give a hesitation on take off but will run because the MAP sensor
> > > determines load and how much fuel to deliver
> >
> > I don't think Chrysler publishes its ECM algorithms, but I've be very
> > surprised if the TPS is used only to sense closed and WOT.
>
> ~Excluding transmission/transaxle functions~
> Rate of change in order to increase the injector pulse width when
> the throttle is opened.
> Idle air control valve diagnostics (fault sensing)
> The TPS is the least important of all the input sensors, its
> biggest effect on fuel delivery is when the PCM is receiving a
> changing voltage from it indicating throttle movement.
>
> > If that were the case, they would use two cheap switches rather than a relatively
> > expensive rheostat sensor.
>
> Some manufactures have been known to do this.
>
> > I'd also be very surprised if they don't
> > make a check for closed throttle when the MAP is indicating low pressure
>
> Closed throttle low MAP pressure is a heavy decel, which is a
> whole different situation from the potential mass vacuum leak
> being discussed.
> A vacuum leak that can/does add hundreds of RPM to idle speed
> -raises- manifold absolute pressure, raising manifold pressure is
> usually responded to by the PCM by as an increased injector pulse
> width.
>
> > and thus calling for more fuel and not rev the engine wildly with a
> > closed throttle. Maybe the Chrysler engineers aren't that smart, but
> > I'm betting they are.
>
> Some things are beyond the limits of control of the system.
>
> > Have you ever seen a Chrysler engine have a vacuum leak that made it run
> > 4,500 RPM with the throttle closed?
>
> You've got a minivan or two at your disposal...
> Hook up your scanner, pull the PCV or brake booster hose off,
> start the engine and report back with the results, i.e., RPM
> changes, MAP changes, pulse width changes.
> You may not see 4500 RPM exactly, but you will experience the
> causes and effect.

??
"mic canic" > wrote in message
...
> hmm could that neil nelson sure types like him
>
> aarcuda69062 wrote:
>
> > In article >,
> > Matt Whiting > wrote:
> >
> > > maxpower wrote:
> > >
> > > > Your right it isnt that nessassary. more of a reference point of
open and
> > > > closed throtlle, u can unhook the tps sensor and the engine will
run, it
> > > > will give a hesitation on take off but will run because the MAP
sensor
> > > > determines load and how much fuel to deliver
> > >
> > > I don't think Chrysler publishes its ECM algorithms, but I've be very
> > > surprised if the TPS is used only to sense closed and WOT.
> >
> > ~Excluding transmission/transaxle functions~
> > Rate of change in order to increase the injector pulse width when
> > the throttle is opened.
> > Idle air control valve diagnostics (fault sensing)
> > The TPS is the least important of all the input sensors, its
> > biggest effect on fuel delivery is when the PCM is receiving a
> > changing voltage from it indicating throttle movement.
> >
> > > If that were the case, they would use two cheap switches rather than
a relatively
> > > expensive rheostat sensor.
> >
> > Some manufactures have been known to do this.
> >
> > > I'd also be very surprised if they don't
> > > make a check for closed throttle when the MAP is indicating low
pressure
> >
> > Closed throttle low MAP pressure is a heavy decel, which is a
> > whole different situation from the potential mass vacuum leak
> > being discussed.
> > A vacuum leak that can/does add hundreds of RPM to idle speed
> > -raises- manifold absolute pressure, raising manifold pressure is
> > usually responded to by the PCM by as an increased injector pulse
> > width.
> >
> > > and thus calling for more fuel and not rev the engine wildly with a
> > > closed throttle. Maybe the Chrysler engineers aren't that smart, but
> > > I'm betting they are.
> >
> > Some things are beyond the limits of control of the system.
> >
> > > Have you ever seen a Chrysler engine have a vacuum leak that made it
run
> > > 4,500 RPM with the throttle closed?
> >
> > You've got a minivan or two at your disposal...
> > Hook up your scanner, pull the PCV or brake booster hose off,
> > start the engine and report back with the results, i.e., RPM
> > changes, MAP changes, pulse width changes.
> > You may not see 4500 RPM exactly, but you will experience the
> > causes and effect.
>

??
"mic canic" > wrote in message
...
> hmm could that neil nelson sure types like him
>
> aarcuda69062 wrote:
>
> > In article >,
> > Matt Whiting > wrote:
> >
> > > maxpower wrote:
> > >
> > > > Your right it isnt that nessassary. more of a reference point of
open and
> > > > closed throtlle, u can unhook the tps sensor and the engine will
run, it
> > > > will give a hesitation on take off but will run because the MAP
sensor
> > > > determines load and how much fuel to deliver
> > >
> > > I don't think Chrysler publishes its ECM algorithms, but I've be very
> > > surprised if the TPS is used only to sense closed and WOT.
> >
> > ~Excluding transmission/transaxle functions~
> > Rate of change in order to increase the injector pulse width when
> > the throttle is opened.
> > Idle air control valve diagnostics (fault sensing)
> > The TPS is the least important of all the input sensors, its
> > biggest effect on fuel delivery is when the PCM is receiving a
> > changing voltage from it indicating throttle movement.
> >
> > > If that were the case, they would use two cheap switches rather than
a relatively
> > > expensive rheostat sensor.
> >
> > Some manufactures have been known to do this.
> >
> > > I'd also be very surprised if they don't
> > > make a check for closed throttle when the MAP is indicating low
pressure
> >
> > Closed throttle low MAP pressure is a heavy decel, which is a
> > whole different situation from the potential mass vacuum leak
> > being discussed.
> > A vacuum leak that can/does add hundreds of RPM to idle speed
> > -raises- manifold absolute pressure, raising manifold pressure is
> > usually responded to by the PCM by as an increased injector pulse
> > width.
> >
> > > and thus calling for more fuel and not rev the engine wildly with a
> > > closed throttle. Maybe the Chrysler engineers aren't that smart, but
> > > I'm betting they are.
> >
> > Some things are beyond the limits of control of the system.
> >
> > > Have you ever seen a Chrysler engine have a vacuum leak that made it
run
> > > 4,500 RPM with the throttle closed?
> >
> > You've got a minivan or two at your disposal...
> > Hook up your scanner, pull the PCV or brake booster hose off,
> > start the engine and report back with the results, i.e., RPM
> > changes, MAP changes, pulse width changes.
> > You may not see 4500 RPM exactly, but you will experience the
> > causes and effect.
>