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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