[Diy_efi] 94-95 5.0 Mustang and a hanging idle...

Wed Jun 14 20:45:44 UTC 2006

yes, same thing here -- subaru guys with manual transmissions were known to
do the opposite, always keep the throttle at 1% so that the fuel cut
mechanism didn't come in when you let off the throttle, made the car coast
nicer as it appears the subaru guys hadn't found a 'nice' way to turn the
fuel back on without violent AWD power 'slams'.

On 6/14/06, Jim Butterfield <jimbutterfield at yahoo.com> wrote:
>
> Jumping in a littlelate here.... but in the GP world before the advent fo
> pcm tuners, we would elongate the two mounting holes on the TPS to optimize
> the settings for 0v and max of 5v ( or 4.9v) closed, and  WOT
>
>   jim
>
> "Lee M. Lemoine" <llemoine at gmail.com> wrote:
>   Keith,
>
> My thoughts are now perhaps turned to the TPS sensor. I remember that on
> my
> Mclaren motor, i had to elongate the mounting holes on the sensor just
> slightly because it kept flickering between 0v and .07v at 'zero'
> throttle,
> which kept causing my idle to surge because of the throttle pump setting
> (picture tapping the throttle constantly)
>
> I'll help you with this when i see you next (read: tomorrow morning) but i
> figured i'd post the response for the group to see / learn from.
>
> Another thought is that we should set the idle for the minimum value (700
> rpm) with the set screw and observe for vaccum leaks pre-MAF and in the
> rest
> of the hard lines on the car -- either with propane or ultrasonically.
> either way, that would cause a surge because i'm pretty sure the way most
> ECM's figure the 'bump' in idle speed is a certain number of 'steps' on
> the
> IAC. perhaps that may be the issue, a difference in diameter of the holes
> in the IAC (overall volume of airflow)
>
>
>
> On 6/13/06, Keith Varin wrote:
> >
> > I am using the TwEECer R/T system to tune my car. I just picked one up
> > from
> > www.promustangperformance.com however i am still new to the unit and
> have
> > not really gotten a grasp of what settings do what. As far as adjusting
> > the
> > idle... I've set the idle adjustment screw so that the car runs and to
> > temporaily get around the hanging idle issue i have actually unplugged
> the
> > IAC motor. I tried replacing it, however it made no difference. Im just
> > wondering why this happened after I installed throttle body, and why it
> > only reacts the way it does when it id raining out...
> >
> > Keith
> >
> > On 6/13/06, Daniel Nicoson wrote:
> > >
> > > Keith,
> > >
> > > What have you done to adjust the idle with the new throttle
> > > body? Normally,
> > > you would disconnect the ignition spout connector, disconnect the IAC
> > and
> > > then manually adjust the throttle plate one "screw-turn" off
> > closed. Then
> > > adjust the idle bleed screw so the engine will idle without any
> computer
> > > help (this would be with every load off, defroster to off, lights off
> > > etc.)
> > >
> > > Once you get it to idle like this (fully warmed up), then turn off and
> > > plug
> > > all back in. See if it is better then.
> > >
> > > If you were tuning the computer with a TwEECer or similar device then
> we
> > > could do more but if you are not modifying computer settings, not much
> > > else
> > > you can do.
> > >
> > > HTH,
> > >
> > > Dan Nicoson
> > >
> > > -----Original Message-----
> > > From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org
> ]On
> > > Behalf Of Keith Varin
> > > Sent: Tuesday, June 13, 2006 10:08 PM
> > > To: Diy_efi at diy-efi.org
> > > Subject: [Diy_efi] 94-95 5.0 Mustang and a hanging idle...
> > >
> > > Hey everyone. First I would like to thank you all for viewing this
> > thread.
> > >
> > > I have a 1994 Ford Mustang Cobra with the 5.0 GT-40 motor and a manual
> > > transmission. It is still relativly stock however with a few small
> mods
> > I
> > > began to have a hanging idle. After installing a new TB and headers
> the
> > > idle
> > > would hang around 1800 rpms. my first thought was that i probably had
> a
> > > leak
> > > in the intake tract somewhere. So i disassembled the intake and
> resealed
> > > everything with rtv and high-tack gasket sealer. The problem went
> away,
> > so
> > > I
> > > figured I had fixed it.Low and behold, 3 days later it was raining out
> > and
> > > I
> > > began my 17 mile trip to work. Halfway there I realized that my car
> was
> > > still idling around 1800rpms, so the work I had done did not fix the
> > > problem.
> > >
> > > I have since paid close attention to the conditions of the environment
> > and
> > > of my vehicle when the idle stays high, here is what I have figured
> out.
> > >
> > > When moving at any speed greater than 15mph with the vehicle in
> neutral
> > or
> > > with the clutch pressed, the car will idle at or around 1100 rpms, and
> > > when
> > > the vehicle comes to a stop it will idle at 800-900 (which is normal).
> > > However, any time it is raining or very damn outside the car will idle
> > at
> > > 1800rpms at any speed 15mph or greater with the vehicle in neutral or
> > with
> > > the clutch pressed.
> > >
> > > If anyone has any input on why my car might be doing this or any ideas
> > on
> > > ways to fix this problem. please feel free to shout it out.
> > >
> > > Thanks
> > > Keith
> > > _______________________________________________
> > > Diy_efi mailing list
> > > Diy_efi at diy-efi.org
> > > http://lists.diy-efi.org/mailman/listinfo/diy_efi
> > >
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> >
>
>
>
> --
> Sincerely,
> Lee M. Lemoine
> KB1NQI - Amateur Radio
> http://www.turbochargedsoul.com/
> '06 Subaru Legacy GT Limited - 250/250 AWD 5EAT
> '93 Chevy Cavalier Z24 Convertible - 300/330 FWD 5MT (Mclaren Turbo!)
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-- 
Sincerely,
Lee M. Lemoine
KB1NQI  - Amateur Radio
http://www.turbochargedsoul.com/
'06 Subaru Legacy GT Limited - 250/250 AWD 5EAT
'93 Chevy Cavalier Z24 Convertible - 300/330 FWD 5MT (Mclaren Turbo!)