O2 Sensor Current?

[Ken Kelly]

Tom,
	I have an 81 307 "Y". It is completely stock, but it isn't
even EFI. It's got the Feedback Carb. I've never played with
it, just been driving it since 85. I don't have a part
throttle ping problem. Maybe you have too much static
advance, carbon buildup, or are running lean. I need to look
at mine, but I actually thought it still had mechanical
advance in the distributor. I thought only the Vacuum
advance was computer controlled. I could be wrong, I've only
replaced the rotor and Cap once on that distributor. I agree
the Feed back carb needs to be replaced, It needs rebuilt
every 2 years, and I've about worn mine out, from
rebuilding.

		Ken

Thomas Martin wrote:
> 
> How would the ECM react or the O2 sensor react with a 1M from O2 sense to GND?
> 
> I will look into the Op Amp circuit, probably best way.
> 
> Has anyone on the list ever decoded the PROM on the 307 "Y" engine?  Is there an older version of code with less part throttle spark advance?  Can
> someone program a chip for me?  I do not have a programmer that will burn the 27S181, I have contemplated adpating a different rom for it, I have one in
> mine, (don't remember it right off hand) but is is nearly pin to pin compatable, but has 2 more than the 27S181.  I have a Data !/O 288A programmer.
> Anyone use one?  It will not read my 27S181, anyone know how I can make it?
> 
> My long term prject is to TBI this car, I think it would be a great running car with a TBI on it, or better yet, SFI.
> 
> Thanks!
> Tom Martin
> 85 Cutlass Supreme Rocket 350 CCC
> 
> >
> >
> > Date: Wed, 24 Mar 1999 22:45:19 -0800 (PST)
> > From: Orin Eman <orin at wolfenet.com>
> > Subject: Re: O2 Sensor current?
> >
> > > This is the standard way of telling if the O2 is at temperature yet... many
> > > systems will bias the sensor to .45 volts through a very high resistance (10
> > > megaohms I believe).  Once the sensor is at temperature, it does provide
> > > enough current to move the voltage away from the preset level.
> >
> > I seem to remember the bias resistors in my ecu were 768k.
> > The O2 sensor's impedance isn't _that_ high or you could never
> > get sensible results looking at it with a regular 1M impedance scope!
> >
> > I beleive it's in the 10 to 100k range when hot.
> >
> > Orin.
> >
> > -----------------