Oxygen Sensor
Huw Powell
audi at humanspeakers.com
Fri May 29 10:47:24 PDT 2015
David,
1. Why do you think the engine is running hot? What tests did you
perform and what were the results?
2. When at idle the ISV rapidly opens and closes, with the duty cycle of
this process determining the amount of air it lets into the engine.
Read my web site.
3. Now you finally tell us you put the wrong fuel pump in your car.
EFI and CIS have very different fuel pressure/flow rate requirements.
What was the original problem that led you to replace the pump?
- Huw
On 5/28/2015 9:23 AM, David Vanden wrote:
> How much do you want for the O2 sensors? Are they Bosch? What type of
> connections do they have? Mine is three wire with the two connections.
>
> I have it idling down to about 950 rpm's which isn't bad. While the
> temperature sensor reads within acceptable limits it seems like the
> engine is running a little hot. I did some tests and I think the
> thermostat is stuck, so that is the next thing to fix.
>
> I think the idle stabilization valve is working. It is definitely doing
> something. When I hook it up and look at it with it getting juice it
> buzzes and stays in one position then opens for a second and immediately
> closes again. I think it must function differently when hooked up to
> the air intake. Does anyone know otherwise?
>
> I have a confession. Part of the reason it has started running a little
> differently is because I installed the Bosch Motorsport 044 fuel pump.
> However, that is causing other problems to be revealed so perhaps it is
> just as well. Once those ideosyncrasies are fixed I hope I can keep
> running it on that fuel pump after all the effort I put into installing
> it. My God is it noisy though. For about 55 dollars I can try to guiet
> it down some by installing Silicone Silencer Cradle Kit for Bosch 044
> Racing Fuel Pump. Has anyone ever tried using one of these? If so,
> what did you think?
>
> Thanks for all the help*.*
>
> David
>
> On Thu, May 28, 2015 at 12:22 AM, <dgraber460 at aol.com
> <mailto:dgraber460 at aol.com>> wrote:
>
> I haven't been following every post or detail, to this point, but
> from the scanning I have done, I am flashing back to my days of
> fighting the idiosynkracies of my stock CIS URQ. I was helped
> incredibly by a few experienced listers, who had tread these paths
> before me. There are too many to name them all, but the late Phil
> Payne, and Huw Powell, talked me off many a ledge.
> What I remember quite clearly is Phil's sage advice that when
> it comes to getting a CIS car to a decent base point there are 3
> main issues to get sorted. They are in order of importance;
> 1. fuel pressure
> 2. fuel pressure
> 3. fuel pressure
> If that isn't sorted, all other specs are chased in vain.
> If you want to swap O2 sensors, I can send you a couple.
> Dennis
> Denver
> -----Original Message-----
> From: David Vanden <dvanden46 at gmail.com <mailto:dvanden46 at gmail.com>>
> To: audi <audi at humanspeakers.com <mailto:audi at humanspeakers.com>>
> Cc: quattro <quattro at audifans.com <mailto:quattro at audifans.com>>
> Sent: Wed, May 27, 2015 11:07 am
> Subject: Re: Oxygen Sensor
>
> Yes, now I feel stupid I was measuring milliohms and not ohms. When
> I measure it in ohms it reads infinity. Another question. How can
> you tell if the Idle stabilization valve is working? On Wed, May 27,
> 2015 at 11:19 AM, Huw Powell <audi at humanspeakers.com
> <mailto:audi at humanspeakers.com>> wrote: > Ah, I see, you have an
> auto-ranging meter, silly me. I still use the > Micronta I got in
> the 80s, which I set to 300 ohms when testing continuity, > so of
> course it goes off-range when "open". > > Yours selects an
> appropriate range. What you are getting is "close enough > to
> infinite" I am sure. You're measuring the resistance of the path >
> through any dirt, insulation, and the air and nothing else. > > And
> good catch, you need that idle switch to actuate before >
> troubleshooting the idle! Remember I said what a pain it is to
> install > correctly "on the car". > > You might want to read a lot
> of this site and digest/bookmark whatever > seems useful, especially
> the middle drop-down on the left (1980-87 4000, > Coupe, UrQ) since
> there is a lot about your car there: > >
> http://audi.humanspeakers.com/index.html > > I hope you also have
> the Bentley repair manual by now. > > - Huw > > On 5/26/2015 10:33
> PM, David Vanden wrote: > >> Well apparently the button on the
> bottom wasn't getting pressed because >> the location of the switch
> must have slipped, so adjusting the location >> of the bottom switch
> tomorrow will be a good place to start. >> >> What was weird was
> after I pressed the bottom switch manually the >> readings for both
> sensors began reading infinity when not pressed. Just >> before that
> the top one was reading 20.82 mohms of resistance when not >>
> pressed and the bottom one was reading approx. 3.82 mohms when not
> >> pressed. I will have to see what they read tomorrow. At least I
> know >> what I have to do with the bottom switch. Thanks all. Good
> Night. >> >> On Tue, May 26, 2015 at 9:39 PM, Huw Powell
> <audi at humanspeakers.com <mailto:audi at humanspeakers.com> >>
> <mailto:audi at humanspeakers.com <mailto:audi at humanspeakers.com?>>>
> wrote: >> >> What DO they read? >> >> Please give us numbers when
> you take measurements... >> >> You don't have to buy a smoke
> machine! EVERY repair shop worth its >> salt will have one, and they
> are simple to set up. >> >> All they do is take very low air
> pressure from a compressor line and >> heat up some special oil to
> make the smoke, IIRC. Pull a vacuum line >> and pump the smoke into
> it. >> >> On 5/26/2015 9:11 PM, David Vanden wrote: >> >> Well I am
> pretty sure I got them wired correctly. The only >> problem, as >> I
> mentioned is that they are not reading infinite when open. >> >>
> There has got to be a way to locate vacume leaks that does >> not
> require >> buying a smoke machine. However, if I did is there a
> model that >> you >> recommend. They come in all shapes and sizes
> and prices on EBAY. >> Anyway, I will debate it more in the morning.
> >> >> David >> >> On Tue, May 26, 2015 at 8:17 PM, Huw Powell >>
> <audi at humanspeakers.com <mailto:audi at humanspeakers.com>
> <mailto:audi at humanspeakers.com <mailto:audi at humanspeakers.com?>> >>
> <mailto:audi at humanspeakers.com <mailto:audi at humanspeakers.com?>
> <mailto:audi at humanspeakers.com <mailto:audi at humanspeakers.com?>
> >>>
> >>
> >> wrote:
> >>
> >> Well,
> they are just switches.
> >>
> >> When closed they should read zero or
> as close as possible
> >> (definitely less than one ohm). When open
> your meter
> >> should just
> >> read off scale/infinite.
> >>
> >>
> They won't "vary" anything, the idle switch tells the ECU
> >> to use
> the
> >> ISV to maintain about 800 rpm (and kills fuel if it is
> >>
> above ~1400
> >> rpm). The WOT switch tells the ECU to go into open
> loop with
> >> a
> >> richer mixture for enhanced acceleration.
> >>
> >>
> - Huw
> >>
> >> I hope you got them wired correctly.
> >>
> >>
> >>
> I soldered a set of the throttle body switches I got.
> >>
> Unfortuneately,
> >> they read they had some resistance as
> opposed to being
> >> infinite
> >> when the
> >>
> switches were not activated. I don't know what
> >> happened to them
> >>
> in the
> >> process of pairing and soldering them. However,
> they
> >> were both at a
> >> perfect 0 when activated so I
> used them. I don't think
> >> they would
> >> increase the
> idle?
> >>
> >> This is a 1987 Audi 4000
> Quattro.
> >>
> >>
> >>
> >>
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