Just jumping onto this topic,but I think we need to
know whether you're using a gauge to measure vacuum,or
using the vehicle's map sensor signal. They work
opposite of each other. Gee whiz,this thread lives on
under a pseudonym.... :)
Thanks!
Steve P.
--- rws <rwsam2002@yahoo.com> wrote:
>
> Jon.
>
> The Vacuum went up to 23-24"/hg when increasing to
> 1500-2000 rpm.
> So,I thought what Bernd said (in another post) was
> that if what I'm
> seeing (increased vacuum) there might be a plugged
> exhaust system,
> true?
>
> Regarding a 'Lab Scope' for automotive applications,
> Autotap is using a
> USB 2.0 port for their OSB-II Scanner, and it cost
> $200.-- That's in my
> price range, but for a PC lab-scope s/w and h/w
> using my own P4 3.3ghz
> P4 17" ws laptop.
>
> I'll start another thread for Auto Lab Scope for PC
> ...
>
>
>
>
>
>
>
>
> Ron
>
>
>
>
>
>
>
> ==================================
> Re: Re: Re: 94 Dak 5.2L Cat Converter Air Pump or
> Air Switch Valve?
> From: jon@dakota-truck.net
> Date: Fri Sep 28 2007 - 19:06:00 EDT
>
>
> rws <rwsam2002@yahoo.com> wrote:
>
> > I did the vacuum test at the intake manifold and @
> idle it's 19"/hg
> > when I raise the throttle quickly it goes to zero,
> if I raise the
> idle
> > to 1500-2000 rpms gradually the vacuum goes up
> about 4"/hg but in
> about
> > 20-30 seconds drops back down to 19"/hg. There may
> be a plugged up
> > converter that is causing this, right?
>
> This sounds normal; at a steady rpm, your vacuum
> should
> eventually return to about where it was at idle.
> When you say the
> vacuum goes "up", do you mean that the numbers go
> up, such that there
> is more vacuum or do you mean that the needle goes
> up, such that the
> numbers are actually going down and there is less
> vacuum? (The proper
> response to opening the throttle should be the
> latter.)
>
> > This is OT but does a lap top PC Oscilloscope
> converter or adapter
> > exist? I was looking at a very nice SW/HW $200
> OBDII Scanner from
> > Autotap.com but want it to be useful for OBD 1
> also. Btw, they have a
> > great tutorial on Sensors.
>
> Yes, they exist but from what I have seen, their
> sampling rate is
> slow compared to an actual scope, so they are of
> limited use,
> depending on what you are trying to measure. (Most
> of them that I
> have seen plug into the paralell port or something
> along those lines,
> which is why the sampling rate is rather slow, but
> if you were to get
> one with its own dedicated PCI card that might be a
> different story.)
> Keep in mind that I haven't looked into them over
> the past several
> years, so things might be different now; I'm not
> really up on what
> might be available. The last time I checked though,
> the PC scopes
> seemed to be limited to somewhere around 25-40 Mhz.
>
> --
> -Jon-
>
> .- Jon Steiger -- jon@dakota-truck.net or
> jon@jonsteiger.com -
>
>
>
>
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