[Fwd: New member needs help]

[J Norris]

Its an aftermarket chip but the stock one reacts the same way.  Everyone I
talked to says that there is no reason the ECM should leave PE mode at that
voltage.  Something else my be causing it.  The guy who made my prom, Fastchip,
suspects the MAF.  He said the ECM will substitute values it thinks airflow
should be when the MAF is bad.  He also told me that swapping out MAF's is the
only way to tell.

Jason

David A. Cooley wrote:

> Actually, looking at the cal for my 95 lesabre, it *should* stay closed loop
> at WOT.  However, it should be a bit richer, like 12.7:1...
> It looks like it's leaving PE mode.  Is this an aftermarket chip or the
> stock cal?
>
> -----Original Message-----
> From: J Norris <jwn at sgi.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Thursday, November 19, 1998 1:47 PM
> Subject: Re: [Fwd: New member needs help]
>
> >That's not my problem.  Mine is going into Closed loop at 4.85 volts TPS.
> At
> >this point it is trying to maintain a A/F ratio of 14.7:1 or 450mv on the
> O2
> >sensor.  Hence a lean condition at WOT.
> >
> >David A. Cooley wrote:
> >
> >> This is from what I have seen on the 84-87 Buick Grand Nationals...
> Looking
> >> at the cal for the 85 shows a limit for TPS high and TPS low errors...
> >> Several other parameters have to be met to turn the check engine light on
> >> and set the code, but coming out of closed loop may be part of the error
> >> (The computer assumes the sensor is shorted and goes open loop with fixed
> >> fuel/timing etc)
> >>
> >> -----Original Message-----
> >> From: J Norris <jwn at sgi.net>
> >> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> >> Date: Thursday, November 19, 1998 11:38 AM
> >> Subject: Re: [Fwd: New member needs help]
> >>
> >> >Very interesting David.  How do you know this?  This seems to be exactly
> >> what my
> >> >car is doing.  The GM service manual says nothing of a high voltage.  Do
> >> you
> >> >know where you read this?
> >> >
> >> >Jason Norris
> >> >
> >> >David A. Cooley wrote:
> >> >
> >> >> At 10:18 AM 11/14/98 +1100, you wrote:
> >> >> >>
> >> >> >Doesn't ECU read high tps as large throttle opening and richen up
> >> >> >accordingly?
> >> >> >I don't understand
> >> >>
> >> >> It does to a point, but it also has a certain level that it uses to
> >> >> determine if the TPS is shorted or open... Depending on the car,
> Usually
> >> it
> >> >> goes to about 4.6-4.7V as normal operation... above that it thinks the
> >> >> wiring or the TPS is shorted.
> >> >> Later,
> >> >> DAve
> >> >>
> >> >> ===========================================================
> >> >>            David Cooley N5XMT           Internet: N5XMT at bellsouth.net
> >> >>      Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
> >> >>        I am Pentium of Borg...division is futile...you will be
> >> approximated.
> >> >> ===========================================================
> >> >
> >> >
> >
> >