Driving with disconnected ISV?
Yvan
start engine on unleaded petrol, and after few minutes ('till engine
warms up) it switches to LPG (see http://www.lpga.co.uk/LPGA.htm). It is
LPG system of an older generation without lambda (O2) gas control.
When I stop the car rpm drops to some 500-600 and then sometimes stalls,
and sometimes goes up to 900-1000 and then back to standard 750.
I was wondering if I can disconnect ISV or switch that goes on when
throttle pedal is released (I can not remember it's name, English is not
my native language), switch that activates ISV. Does that switch do
something else? Could i do any damage by disabling it? Or by
disconnecting ISV?
On LPG system I can adjust idle by turning a knob, but it seems that ISV
is slow in reaction when throttle pedal is released, so to confirm that
I want to try driving with ISV disconnected, but I am afraid of possible
damage to other systems.
--
___ ____
/__/ / \ ** Registrovani korisnik Linuksa #291606 **
/ / \/ /\ \ ** http://counter.li.org/ **
/__/\____/--\__\ ** Reply at: iimperl - at - ml1 - dot - net **
Steve Sears
I must admit I have no knowledge of the LPG system or how it runs. With a
normal engine, the throttle switch tells the idle stabilization system when
the throttle is at idle, and the ISV should regulate rpm. It sounds like
you have a sticky ISV - which you should clean with _throttlebody cleaner_
(NOT CARBURETOR CLEANER), or check the condition of the throttle switch. If
the ISV is a 2 contact unit, if you can blow through the unit (after it's
cleaned, of course) without power, then it's no good. If it's a 3 contact
unit, then it is supposed to allow air through at rest. When you clean the
ISV, use a 9volt battery to make the valve click to ensure that it is not
siezed. If the LPG system acts like a normal fuel system, the shutdown of
the switch or of the ISV shouldn't harm it, it will just idle poorly.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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"Yvan" <m...@privacy.net> wrote in message
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Yvan
| It sounds like you have a sticky ISV - which you should clean with
| _throttlebody cleaner_(NOT CARBURETOR CLEANER), or check the condition
| of the throttle switch.
Throttle switch is OK it goes on just when it is suppose to, and I
cleaned ISV with carburetor cleaner :-( and 9 V battery. Everything
works OK running on petrol, it's LPG that is troubling me.
Hire is in short how it works: Engine is always started on petrol, and
runs on petrol for few minutes, until engine warms up. Then it switches
to LPG. LPG is in liquid state in tank, goes to evaporator (warmed with
coolant from car cooling system so it does not freeze), and there it
evaporates and goes into intake mainfold trough rubber hose. When engine
idles LPG is going trough ISV. So all the electronic, O2 sensor... have
no effect when engine is running on LPG. Sort of very simple carburetor.
Only thing that can be adjusted is idle (with a knob on evaporator).
Since ISV is constantly working I have trouble adjusting idle so I try
to disconnect it but engine died. So it seems that my idea about running
engine with ISV disconnected is no good :-)
| If the ISV is a 2 contact unit, if you can
| blow through the unit (after it's cleaned, of course) without power,
| then it's no good.
It's 2 contact unit, I'll try that.
| If it's a 3 contact unit, then it is supposed to
| allow air through at rest. When you clean the ISV, use a 9volt
| battery to make the valve click to ensure that it is not siezed.
Did that while I was cleaning ISV, it is working. I also did the test by
inserting fuse in one of relay's in fuse box for few seconds, and than
by activating full throttle switch, and it's clicking.
| If the LPG system acts like a normal fuel system, the shutdown of the
| switch or of the ISV shouldn't harm it, it will just idle poorly.
As I said it does, so much for my idea.
BTW how do you adjust timing on this car, how do you loosen distributor
when there is bolt at it's base?
I hope you can understand what I am writing, my English is far from
perfect, and I still have to learn all mechanic words :-)
Steve Sears
Although I can't vouch for this, I have heard that you cannot adjust timing
by turning the distributor - as I understand it (or misunderstand it), the
crank position sensor (a magnetic sensor which picks up the passing of a
timing pin on the flywheel) tells the engine control unit when the engine is
at top dead center for cylinder 1, and the engine is run accordingly using
the hall sensor in the distributor as a secondary reference.
Somebody...help me out on this one.....
When you say that LPG is going through the ISV - is the LPG hose connected
to the valve itself, or the intake? The ISV in a normal car acts like a
controllable vacuum leak to stabilize the rpm of the car by controlling the
rise and fall of the metering plate - more vacuum in the manifold ~ plate
rises ~ more gas injected ~ rpm increases. The ISV is designed to leak
unmetered (and unexplosive) air into the engine to drop the plate - if you
have the LPG connected to the ISV so it is leaking explosive LPG.....hmmm.
This might explain how disconnecting the ISV will result in the engine
dying - when the power to the ISV is shut off, the ISV is shut off (or
almost off if it is leaking) - so no LPG to the engine. If sounds to me
like the change in function of the ISV (from a vacuum leak to a fuel
injector) might be the problem with the oscillating idle - when it opens up,
it is expecting to let in more air which would normally drop the metering
plate and reduce the idle - but in this case the opening of the ISV results
in more fuel (LPG) into the engine.....is this right?
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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"Yvan" <m...@privacy.net> wrote in message
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Yvan
| Yvan,
| Although I can't vouch for this, I have heard that you cannot adjust
| timing by turning the distributor - as I understand it (or
| misunderstand it), the crank position sensor (a magnetic sensor which
| picks up the passing of a timing pin on the flywheel) tells the engine
| control unit when the engine is at top dead center for cylinder 1, and
| the engine is run accordingly using the hall sensor in the distributor
| as a secondary reference. Somebody...help me out on this one.....
OK, I was just wondering... Thanks.
| When you say that LPG is going through the ISV - is the LPG hose
| connected to the valve itself, or the intake?
LPG hose (actually two of them - one for idle, and one for all but not
idle - sorry for mu bad English again) is connected to air/fuel mixer
located in front of intake. From air/fuel mixer one hose is going to
angled elbow and from there one small hose to intake, and one bigger to
ISV.
| The ISV in a normal car
| acts like a controllable vacuum leak to stabilize the rpm of the car
| by controlling the rise and fall of the metering plate - more vacuum
| in the manifold ~ plate rises ~ more gas injected ~ rpm increases.
| The ISV is designed to leak unmetered (and unexplosive) air into the
| engine to drop the plate - if you have the LPG connected to the ISV so
| it is leaking explosive LPG.....hmmm. This might explain how
| disconnecting the ISV will result in the engine dying - when the power
| to the ISV is shut off, the ISV is shut off (or almost off if it is
| leaking) - so no LPG to the engine. If sounds to me like the change
| in function of the ISV (from a vacuum leak to a fuel injector) might
| be the problem with the oscillating idle - when it opens up, it is
| expecting to let in more air which would normally drop the metering
| plate and reduce the idle - but in this case the opening of the ISV
| results in more fuel (LPG) into the engine.....is this right?
I think that hose that is going to the ISV delivers LPG/air mixture, not
just pure LPG.
I was wrong when posting my original post stating that engine works OK
on unleaded fuel. Today since my engine stalled almost every time I
stopped in on red traffic light, I switched back to gasoline, and engine
then did not die, but it goes to some 650-700 rpm, shakes, then goes to
800-850 rpm and than back to 750 that it should be idling.
So since timing can not be adjusted, and I changed spark plugs, I should
probably change distributer cap, rotating arm in distributer. Can O2
sensor give that symptoms? I tested it and it oscillates 0.35 V (.17 up
an d .17 down) but it takes 1.2 sec (should be .3 sec). I am not willing
to change it, because I think that it has no role when driving on LPG (I
am not sure about that). Also where I live monthly income is low, (I as
a system administrator in a firm with 500 employees make 300$ for a
month) so I am trying to do repairs myself, and Audi part prices are the
same or higher than in US. I could sell this car, but I love it so much
it is good and served me well for 6 years, I just have to fix this idle
thing.
Steve Sears
If the ISV is delivering a mixture of LPG and air, that is still more
burnable than the air it is supposed to deliver. The ISV is usually opened
to drop the metering plate to reduce the amount of fuel going into the
engine - but when your ISV opens, it is letting more LPG into the engine.
It sounds backwards to me.
I would change the cap and rotor as a maintenance item, but if the original
oxygen sensor is still in the car I would consider changing it - doubly so
if the convertion to LPG used any silicone sealants to seal the hose
connections (silicone will coat the OXS). If you can get a cheap price on
_any_ 3-wire oxygen sensor, I would get one and splice it into the Audi
harness, or get to know some local Audi owners and borrow one to see if the
change changes anything - get togethers at pubs are helpful - the flow of
beer seems to increase the loaning of tools and selling of spare parts for
less money ;-)
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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> I think that hose that is going to the ISV delivers LPG/air mixture, not
Yvan
| If the ISV is delivering a mixture of LPG and air, that is still more
| burnable than the air it is supposed to deliver.
Yes, but since there is no gasoline it must be LPG-air mixture.
| The ISV is usually
| opened to drop the metering plate to reduce the amount of fuel going
| into the engine - but when your ISV opens, it is letting more LPG into
| the engine. It sounds backwards to me.
| I would change the cap and rotor as a maintenance item, but if the
| original oxygen sensor is still in the car I would consider changing
| it - doubly so if the convertion to LPG used any silicone sealants to
| seal the hose connections (silicone will coat the OXS).
Yes there is some red stuff that looks like silicone sealant where
air/LPG mixer is located. I just wonder if it is necessary. Does O2
sensor have any influence on anything else but amount of injected fuel?
If not I would be changing it for nothing since I drive 99% of time on
LPG. I tried to disconnect it, but it seems to have no effect on idling
whether engine is on LPG or gasoline. But it's definitely not working as
it should I tested it by some instructions provided by Bosch with
oscilloscope.
| If you can
| get a cheap price on_any_ 3-wire oxygen sensor, I would get one and
| splice it into the Audi harness, or get to know some local Audi owners
| and borrow one to see if the change changes anything - get togethers
| at pubs are helpful - the flow of beer seems to increase the loaning
| of tools and selling of spare parts for less money ;-)
Ha, interesting idea :-) If you think that O2 sensor does have effect on
something else than amount of injected fuel I will buy one and replace
it. Maybe it will not better things, it certainly will not do any bad.
Steve Sears
Ideally, I believe that the LPG go through the main intake _only_ and not
also through the ISV.....but I'm sure that the people who designed the
system know their stuff. The use of silicone sealant is troublesopme,
though.
Check out:
http://www.sjmautotechnik.com/trouble_shooting/10vo2sen.html
The oxygen sensor feeds back to the engine control unit, which does figure
in to the idle of the car. Part way down Scott mentions that carbon plugged
slots in the OXS will result in fluctuating idle mixture and idle speed.
That _may_ be your culprit.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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"Yvan" <m...@privacy.net> wrote in message
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Yvan
| Ideally, I believe that the LPG go through the main intake _only_ and
| not also through the ISV.....but I'm sure that the people who designed
| the system know their stuff. The use of silicone sealant is
| troublesome, though.
| Check out:
| http://www.sjmautotechnik.com/trouble_shooting/10vo2sen.html
| The oxygen sensor feeds back to the engine control unit, which does
| figure in to the idle of the car. Part way down Scott mentions that
| carbon plugged slots in the OXS will result in fluctuating idle
| mixture and idle speed. That _may_ be your culprit.
Yes, but disconnecting O2 sensor for a while should solve my problem,
and then I could buy new one.
What about deceleration valve? Do I have one? Could stuck decel valve be
my problem?
I borrowed one ISV from a guy that sells used Audi parts. He only had
one like this:
http://www.sjmautotechnik.com/trouble_shooting/ecupic/idlesta2.jpg
which is slightly different then one I have. Borrowed one passed blowing
test (as you mentioned it should be closed with no power). Mine did not,
but looking at how it operates I am almost sure that that is the way it
is suppose to be. With ISV in horizontal position there is a 1 mm gap on
the top of a rotating metal thing that can be seen on the "in" side of
ISV. With 9V power rotates up first closing mentioned 1 mm gap and then
opening gap below it. I hope you can understand this :-)
Anyway, fitting other ISV did not do anything, problem is still hire.
Again I was wondering about decel valve. Perhaps if I have one I could
temporarily disable it to see if it is stuck? As I understand it should
be somewhere on air filter box. I will check tomorrow (hire is night
now) but it would help if I would knew what it looks like.
Steve Sears
The system in the 1987 Audi 5000 Turbo/200 used a deceleration valve, the
failure of which could result in the engine stalling (it cuts the fuel
delivery off to the engine when the car decelerates, thus reducing fuel
consumption) - but that is for the fuel system, which your LPG system is not
using. There's a Russian web site that has all the parts diagrams - if you
ask the collective at www.audifans.com - I'm sure someone will send you the
link to the site (it's often referred to as the "Family Album").
I think you should give all of the intake hoses a real close check for
cracks or leaks - also in the connections between the LPG system and the
car's original system hoses - the underside of the intake hoses rots out
first due to oil from the crankcase recirculation (and turbo leaks). When
the car is idling, the intake is under a vacuum and may cause an
intermittent leak in a broken hose - changing the fuel/LPG mixture and thus
the idle.
Yvan
| The system in the 1987 Audi 5000 Turbo/200 used a deceleration valve,
| the failure of which could result in the engine stalling (it cuts the
| fuel delivery off to the engine when the car decelerates, thus
| reducing fuel consumption) - but that is for the fuel system, which
| your LPG system is not using.
Yes, but from:
http://www.sjmautotechnik.com/trouble_shooting/ecusys.html#decel
"These valves have been known to stick open and then not shut when the
RPM drops below 1200 which causes the big vacuum leak and the stalling"
So if deceleration valve is not completely stick, but slow in response
(close to sticking, but still works) I would have vacuum leak. I do not
knew if this is possible.
| There's a Russian web site that has all
| the parts diagrams
Yes, I knew, I found it some time ago, its:
http://www.elcats.ru/audivw/nn/
I was searching there and on page:
http://www.elcats.ru/audivw/nn/vag4.asp?gid=1&cid=79&motor=&myear=1988&cyl=&vol=
when you click on nine-th item from the top, and then on the button
below the picture on the left, (NF engine) there is no decel valve. But
if you click on the eighth item from the top and then on the button
below the picture on the left, (MC engine) there is one. So it seems
that I do not have one.
What about EGR valve? Where is it? I can not find it either on Russian
site. Do I have it? Can that be the problem?
| I think you should give all of the
| intake hoses a real close check for cracks or leaks - also in the
| connections between the LPG system and the car's original system hoses
| - the underside of the intake hoses rots out first due to oil from the
| crankcase recirculation (and turbo leaks). When the car is idling,
| the intake is under a vacuum and may cause an intermittent leak in a
| broken hose - changing the fuel/LPG mixture and thus the idle.
I already checked intake hoses. Only breather hose was broken, and I
replaced it.
Steve Sears
I think that the oxygen sensor and the catalytic converter led to the demise
of the EGR valve - my 1980 5k (WD-code engine) has one (and no OXS or cat.
converter), but my 1987 5ktq (MC-code engine) does not.
Yvan
| I think that the oxygen sensor and the catalytic converter led to the
| demise of the EGR valve - my 1980 5k (WD-code engine) has one (and no
| OXS or cat. converter), but my 1987 5ktq (MC-code engine) does not.
Thanks for all your help. I will check once again all the vacuum hoses,
maybe replace some of them will ones for fuel or radiator hoses be good?
If nothing gets better I'll have admit defeat and go to mechanic :-(
Steve Sears
Someone on Audifans wrote that using an _UNLIT_ propane torch (with the car
outside in a well ventilated area, etc. etc.), you could find intermittent
vacuum leaks by flowing the stream of propane gas over the intake hoses with
the engine running. If the engine rpm raised with the torch tip near a hose
or connector, there would be a good chance there was a leak in that area.
I've never done that test, and of course you know that propane can burn and
blow stuff up, but it's a test others have used successfully.
No probs on the help.
Yvan
| Someone on Audifans wrote that using an _UNLIT_ propane torch (with
| the car outside in a well ventilated area, etc. etc.), you could find
| intermittent vacuum leaks by flowing the stream of propane gas over
| the intake hoses with the engine running. If the engine rpm raised
| with the torch tip near a hose or connector, there would be a good
| chance there was a leak in that area. I've never done that test, and
| of course you know that propane can burn and blow stuff up, but it's a
| test others have used successfully. No probs on the help.
Thanks again for all your help.
Wolfgang Pawlinetz
>I've never done that test, and of course you know that propane can burn and
>blow stuff up, but it's a test others have used successfully.
Can't one just use startpilot? Startpilot is a spray which is useful
for carburator engines if they don't want to start. Spray it into the
air intake during turning of the engine. I suppose it's alcohol or
ethane.
Should provide the same result as it's made for that purpose, but it
could possibly be a bit safer than propane.
Don't know, however, what the english brandname is.
Regards
Wolfgang
--
1999 Audi A6 Avant TDI
Steve Sears
That sounds like the "Quickstart" that my dad used to use to get the old '68
Dodge Monaco going on cold mornings - it's ether. I've also heard of using
WD40. The propane method sounds good because you're not waiting for the
last spot you sprayed to dry up before you move on to check a different
hose.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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Yvan
| Wolfgang,
| That sounds like the "Quickstart" that my dad used to use to get the
| old '68 Dodge Monaco going on cold mornings - it's ether. I've also
| heard of using WD40. The propane method sounds good because you're
| not waiting for the last spot you sprayed to dry up before you move on
| to check a different hose.
It sounds dangerous to me. If I have bad spark plug wire, or exhaust is
leaking, I cold burn car or myself :-)
Yvan
| The propane method sounds good because you're
| not waiting for the last spot you sprayed to dry up before you move on
| to check a different hose.
Does my (5 cyl, 2.3 NF normally aspirated) engine have PCV (positive
crankshaft ventilation) valve? If it does, where is it? I'd like to
check it.
Steve Sears
No, I don't believe that it has a valve, but it should have a vent hose that
collapses over time.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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"Yvan" <m...@privacy.net> wrote in message
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Yvan
| No, I don't believe that it has a valve, but it should have a vent
| hose that collapses over time.
OK, thanks. I recently replaced that hose.
Yvan
I disconnected ISV electrical connector, and result is that engine idles
OK when warm (50 deg Celsius or more). The higher the engine
temperature, the higher the RPM, but no more than ~900.
When I stop, rpm does not drop low to ~600 rpm and then up to ~900 and
then to normal 750 as it does with ISV connected. It just goes down to
to ~900 or less depending on engine temperature.
Am I right to assume that my problem is ISV?
How do I find out if it is exactly ISV an not some sensor somewhere that
sends wrong signals to ECU? I have oscilloscope and digital multimeter
so I would appreciate if anyone can give me details, or point me to some
url on the net with detailed specification of voltages (or any other way
to determine what is not functioning correctly).
I ordered Haynes manual from haynes.co.uk, but it has not arrived yet.
Tony
Also, What car is this?
If a T44, you might want to see numerous threads on this at Audiworld:
http://forums.audiworld.com/v8/
The ISV is operated with the ISV controller (in T44s it is in drivers side under
dash in Aux relay panel).
One input that it uses is a temp sender (on T44, I5 it is under the upper
radiotor hose)
Yvan
| I do not see a thread where you described what problem you are trying
| to correct.
I have problem that I briefly described in my previous post. When I
stop the car rpm drops to some 500-600 and then sometimes stalls, and
sometimes goes up to 900-1000 and then back to standard 750.
| Also, What car is this?
1989 Audi 100 2.3E (NF 5-Cyl. engine).
| If a T44, you might want to see numerous threads on this at Audiworld:
| http://forums.audiworld.com/v8/
It is not V8.
| The ISV is operated with the ISV controller (in T44s it is in drivers
| side under dash in Aux relay panel).
|
| One input that it uses is a temp sender (on T44, I5 it is under the
| upper radiotor hose)
I found some instructions here:
http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture
but it seems it is not for my NF 5-Cyl. engine. But I am going to test
it like this anyway.
Steve Sears
Yvan has a Type $$, but he's running an LPG convertion on his car. You'd
have to look at the a.a.a archives to see the troubleshooting that went on a
couple of months ago.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
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"Tony" <tonyj...@nospamvisi.com> wrote in message
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Steve Sears
The temperature:rpm correlation should be about right, as the LPG will turn
to a more diffuse gas with greater heating, and you are using the engine
coolant to heat the LPG, right?
It sounds like the ISV is indeed working, but the feedback from it being
designed for a different purpose than LPG sounds like it may be causing the
problem (by working properly!) - I suggest that you may have to rig in a way
to disable the ISV when you are running LPG, as the engine runs properly
when you're running on gasoline, correct? Thus, when the LPG turns on
(engine at required temperature), then you would have to take the ground
connection away from the ISV. I expect that there may be a relay doing that
already - to shut off the fuel pump.
BTW, the Audiworld type 44 (aka type $$) forum, which covers 100/200/5000/V8
(and, apparently 500 in South Africa and other places) - appears as:
http://forums.audiworld.com/v8/
- it's not just V8's covered in there
And the "Haynes" manual?.......ugggh! When you read "Assembly is the
reverse of removal" you'll realize why the Bentley Manual is worth the extra
$ for those who actually do work on their car.
Steve Sears
1987 Audi 5kTQ - Bentley Manuals (2 volumes) referred to often
1980 Audi 5k - Bentley Manuals (2 copies of 1 volume) close at hand -
Haynes/Chiltons manuals use to keep Bentley Manual pages from blowing aroung
as I work outside - and as Joke Books
1962 and '64 Auto Union DKW Junior deLuxes - pre-Bentley Factory Manuals (in
German and English) in use....along with Babelfish
Randolph
Yvan wrote:
> I have problem that I briefly described in my previous post. When I
> stop the car rpm drops to some 500-600 and then sometimes stalls, and
> sometimes goes up to 900-1000 and then back to standard 750.
>
> | Also, What car is this?
>
> 1989 Audi 100 2.3E (NF 5-Cyl. engine).
I have an '87 VW Golf GTi with CIS-e (= KE-Jetronic) fuel injection. I
too had a problem with idle speed earlier this year. I first suspected
the ISV and replaced it (the replacement cost me $4, so replacing it was
cheap troubleshooting). No change. I then found out the the idle
position switch (the switch that closes when you release the gas pedal)
was broken. The fuel injection system would never know to get into idle
mode, and thus the idle speed was off. A new switch (they are sold only
in a set with the wide open throttle switch for my car) was over US$100
from the dealer so I went to a local junkyard. What I found was that a
large number of both Audis and VWs at the junkyard had broken idle
position switches, so it seems to be a common problem for VAG vehicles
of that vintage. I eventually found a working one from a slightly newer
car with Digifant, not CIS-e. The switch is the same for the two, but
the wiring is different. The switches are located on the throttle body,
on mine there is one switch in plain view on top, which is the WOT, or
wide open throttle switch, and another underneath the throttle body.
This is the idle switch. Your car may be different.
I don't know what type of fuel injection you have on your car, but I
believe you said you do not have an oxygen sensor. That would be
consistent with CIS (= K-jetronic), and I believe (but am not sure) that
CIS uses the same switches as CIS-e. The simplest test of the switch is
to open the hood and move the throttle by hand between closed and barely
open. If the switch is working, you should hear the clicks at is turns
on and off. The broken switches I have seen have had the plunger fall
out, so that the switch would not operate at all. Another test is to
disconnect the switch and short the two wires that goes to it. If
shorting the wires make the idle go back to normal, you can be pretty
sure there is a problem with the switch.
Yvan
| The temperature:rpm correlation should be about right, as the LPG will
| turn to a more diffuse gas with greater heating, and you are using the
| engine coolant to heat the LPG, right?
I think that engine coolant is used only to keep vaporizer from freezing
and it perhaps heets lpg spmewhat, but I think that does not make any
difference.
| It sounds like the ISV is indeed working, but the feedback from it
| being designed for a different purpose than LPG sounds like it may be
| causing the problem (by working properly!) - I suggest that you may
| have to rig in a way to disable the ISV when you are running LPG, as
| the engine runs properly when you're running on gasoline, correct?
No. It is the same, gasoline or lpg, I did some more testing. Perhaps a
problem is not so big on gasoline as it is on lpg, but it is there.
| Thus, when the LPG turns on(engine at required temperature), then you
| would have to take the ground connection away from the ISV. I expect
| that there may be a relay doing that already - to shut off the fuel
| pump.
I can install a switch to disconnect ISV, but as I just wrote I have the
same problem with gasoline too.
| BTW, the Audiworld type 44 (aka type $$) forum, which covers
| 100/200/5000/V8(and, apparently 500 in South Africa and other places)
| - appears as: http://forums.audiworld.com/v8/
| - it's not just V8's covered in there
I will check thaere, thanks.
| And the "Haynes" manual?.......ugggh! When you read "Assembly is the
| reverse of removal" you'll realize why the Bentley Manual is worth the
| extra$ for those who actually do work on their car.
It seems like I will have to get the Bentley Manual, I just received
Haynes manual for '77 Puch Maxi that I own, and I am completely
disappointed. It looks like "complete idiots guide" to disassemble and
assemble moped's engine. I did that without the manual.
Yvan
| > | Also, What car is this?
| >
| > 1989 Audi 100 2.3E (NF 5-Cyl. engine).
|
| I have an '87 VW Golf GTi with CIS-e (= KE-Jetronic) fuel injection. I
| too had a problem with idle speed earlier this year. I first suspected
| the ISV and replaced it (the replacement cost me $4, so replacing it
| was cheap troubleshooting).
ISV for my car is $220 (BOSCH 0 280 140 512) Audi part 034 133 455B is
probably more $$.
| No change. I then found out the the idle
| position switch (the switch that closes when you release the gas
| pedal) was broken.
One on my car works OK. I checked.
| I don't know what type of fuel injection you have on your car, but I
| believe you said you do not have an oxygen sensor.
I have O2 sensor.
Tony
Yvan wrote:
> Nedavno Tony pise:
>
> I have problem that I briefly described in my previous post. When I
> stop the car rpm drops to some 500-600 and then sometimes stalls, and
> sometimes goes up to 900-1000 and then back to standard 750.
>
> | Also, What car is this?
>
> 1989 Audi 100 2.3E (NF 5-Cyl. engine).
>
> | If a T44, you might want to see numerous threads on this at Audiworld:
> | http://forums.audiworld.com/v8/
>
> It is not V8.
The forum link that I gave is for all Type 44s ('82 to '91) and most of the
discussion is for the five cylinder engines.
> | The ISV is operated with the ISV controller (in T44s it is in drivers
> | side under dash in Aux relay panel).
> |
> | One input that it uses is a temp sender (on T44, I5 it is under the
> | upper radiotor hose)
>
> I found some instructions here:
>
> http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture
Very good source for information. SMJ site is nearly the 'bible' for T44 series.
> but it seems it is not for my NF 5-Cyl. engine. But I am going to test
> it like this anyway.
>
That would be a good start.
Good luck.
Tony
'91 100q 5spd
ISV BTDT
Tony
just opposite from gas due to the location of the LPG infection.
Tony
Yvan
| It sounds like the ISV is indeed working, but the feedback from it
And am I right to assume that there is no vacuum leak, since when I
disconnect electrical connection to ISV, when I stop, rpm does not drop
low to ~600 rpm and then up to ~900 and then to normal 750 as it does
with ISV connected.
--
Yvan
| And the "Haynes" manual?.......ugggh! When you read "Assembly is the
| reverse of removal" you'll realize why the Bentley Manual is worth the
| extra$ for those who actually do work on their car.
You are right! Just got my Haynes. Not much to help me solve my problem.
There is no information where is located ISV Control Unit for my car. I
wanted to test it according to:
http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture
but when I removed driver side parcel shelf I could not find it. There
were only few relay's and connectors.
Anyone knows location of ISV Control Unit on 5-cyl. 1989 Audi 100?
Tony
under dash on left hand drive cars). It looks like a relay but is double the
width of a normal relay. Bottom row of relays.
Yvan
| Bentley says that it should be in the aux relay panel (by drivers left
| knee under dash on left hand drive cars). It looks like a relay but is
| double the width of a normal relay. Bottom row of relays.
| >
| > Anyone knows location of ISV Control Unit on 5-cyl. 1989 Audi 100?
I looked there, only 4-5 wire connectors and 2-3 relays, none of them
wider than normal. I will look again soon (to cold now).
Or is it different on European models? Anyone from Europe?
Steve Sears
You might want to look close to the relays you have found, in my 1987 5ktq
there are a set of relays accessable by a cover, but there are also some
relays mounted beside them.
Cheers!
Steve Sears
1987 Audi 5kTQ
1962 and '64 Auto Union DKW Junior deLuxes
Yvan
| You might want to look close to the relays you have found, in my 1987
| 5ktq there are a set of relays accessable by a cover, but there are
| also some relays mounted beside them.
I took some pictures:
http://photos.yahoo.com/perlica
Black box that I outlined with red color is Bosch car alarm. Nothing
looks like ISV Control Unit. Am I looking at right place? Look at first
two photos.
Tony
Like I mentioned before, that is where it should be. I remember someone
commenting on the Audiworld form (T44 / V8) that some years controlled the ISV
from the ECU but I am not sure if that is correct and what years it would
involve. You may want to ask the question there as well.
Tony
Yvan
| That is where you should find it.
|
| Like I mentioned before, that is where it should be. I remember
| someone commenting on the Audiworld form (T44 / V8) that some years
| controlled the ISV from the ECU but I am not sure if that is correct
| and what years it would involve. You may want to ask the question
| there as well.
I will, thanks.
Yvan
| You might want to look close to the relays you have found, in my 1987
| 5ktq there are a set of relays accessable by a cover, but there are
| also some relays mounted beside them.
I found ISV control unit. It is integrated with fuel injection control
unit, and is under right side kick panel, and ISV is connected to it. I
checked connection and it is OK.
Ignition control unit is under left side kick panel, and idle and full
throttle switches are connected to it (and the connection is OK, and
switches work as they should).
Since I did not knew how to fix my idle problem proper way I decided to
do the only way I knew. I cut the wire from fuel injection control unit
to ISV just in front of fuel injection control unit, and then used rear
fog light switch on the dash for connecting and disconnecting ISV.
Hire is how it now works: I switch ISV on, start the car, and drive for
a while until engine warms up to ~50 degrees Celsius. I then hit the
switch, and disconnect ISV, and engine revs nicely around 800 rpm. No
stalling - hesitating then. Not the best solution, but it works.
I was wondering if I could do some damage by disconnecting ISV while
engine is running?
Am I right to assume that there is no vacuum leak if engine does not
stall with ISV disconnected?
And since idle switch works, and its connection to ignition control unit
is OK, as is ISV - fuel injection control unit connection, perhaps ISV
is my problem. On the other hand I cleaned ISV with carburetor cleaner
(I should use throttle body cleaner as I learned later), and checked it
with 9V battery, it seemed OK to me. And I did put another ISV (but not
from NF engine, it was slightly different), and my problem did not go
away:-(
Anyway I temporarily solved my stalling/idle problem.