[Shotimes] BARO sensor

[Carl Prochilo]

One of the things that I would have expected a datalogger to do is
show all the sensor inputs to the PCM and their values.  Because the
BAP can affect A/F mixture, this would be one of the key sensors.

I remember reading a long time ago that you could tap the BAP sensor
lead and measure a very small voltage change as you operate the
throttle as a way of verifying the operation of the sensor.  If you
have a datalogger this should be much easier.  Can someone that knows
these values please post them here?

Finally, what are the correct values the BAP should be posting to the
PCM at sea level.
-- 
Cheers,
Carl Prochilo
92 Ultra Red Crimson

On Sat, September 17, 2005 12:57, Kevin & Cheryl Airth said:
> Tim The Tool Man:
> Great screen name!
> That's a tough one to troubleshoot. It very well could be the cause of
> your
> lean running but then again maybe not? The easiest way is just to swap
> sensor's. There have been several long term drivability problems that
> were
> finally found to be the BP sensor but no code was set. The sensor was
> still
> operating in the correct range of values but was not changing at all.
> This
> made the car drive OK at some engine speeds and loads and to be WAY
> off in
> other conditions. It's mainly used as an altitude compensation device
> so the
> closer to sea level you drive the less of an effect a bad BP sensor
> will
> have.
>
>  Do you have access to another sensor?
>
>  The sensor can be checked with a frequencies counter. Yea, I know who
> has
> one of these? Anyway at sea level you should be seeing around 160-170
> Hz. As
> you apply vacuum to the open port the frequency should decrease to a
> low of
> somewhere around 90Hz. The sensor has 3 wires. One is the 5 VDC
> supply, one
> is a ground and the middle pin on the sensor should be the changing
> output.
> I do have instructions for using a tachometer to read the frequency.
> Set it
> on 4 cylinder setting and you should see 4800 rpm with no vacuum and
> the
> rpm's should decrease with increasing vacuum.
> .
> .
>
>
>
>> What symptoms will I see (if any) of a bad BARO sensor?
> _______________________________________________
> Shotimes mailing list
> Shotimes@autox.team.net
> http://www.team.net/mailman/listinfo/shotimes