Recall question, 1991 Jetta, computer
sonodude
crapped out. Since the unit is expensive to replace and I am unable to find
a working used model, does anyone know if the part has been recalled? I
went on the NTSB (or whatever) website and nothing came up. I know there
are these secret warranties and recalls so if you know of any and would like
to share them with me, I'd greatly appreciate it. Many thanks in advance.
GK
Bob Hetzel
for years and probably less than 1 in 10 posts where a person says they
replaced the computer to try to fix a problem it worked.
Most times it's a far cheaper part that goes...
In article <T_MDa.108$oD6....@news.on.tac.net>,
sonodude
salient points. I've had this recurring problem where my car starts fine,
then after about 3-5 minutes of driving it starts into this rough idling,
poor acceleration and black smoke pouring out of the tailpipe, but doesn't
stall. I can remedy this by two methods. One is to stop and turn off the
engine, wait five minutes and then start it again. The car will run fine
for a few days before these symptoms occur again. The second way to remedy
is to disconnect the first temp sensor in the coolant line coming off the
engine block. The engine defaults into a slightly higher idle, but it runs
smooth.
Let me now say that this was going on for the last two months ago. In the
last couple of weeks this problem now happens constantly and I am left with
driving around with the temp sensory disconnected all the time. In fact, at
any time now I can reconnect and disconnect this temp sensor repeadily and
watch as the engine runs rough, then smooth, rough, then smooth, etc.
I would also like to add that I had some other work done with another
hesitation/stalling problem in January.
This is what has been done so far. The temp sensors have been replaced
three times (current ones are one week old). Also, in the last 6 months, I
have replaced the fuel pressure regulator, O2 sensor, idol regulator, ais
slider valve, starter. The car was also tuned up a year and a half ago.
My mechanic and I have been racking our brains. He has run some voltage
tests on my computer and says that for known 5V signals the computer should
be returning the signal, but it isn't (I think I have explained this
properly, but it was a little too technical for me to articulate properly
here). The computer seems to be the only thing left. What else could it
be?
I love my Jetta and other than this the car has given me 255,000 kms of
great driving. I am ready to sell it, but I cannot do so with a clean
conscience until this problem is solved.
If you have any suggestions, I would really appreciate it.
"Bob Hetzel" <b...@blackout.DMS.cwru.edu> wrote in message
news:bbob0o$c3t$1...@blackout.DMS.cwru.edu...
Bob Hetzel
I'd next try to look at the plug wires and the plugs.
If it's been running crappy for any length of time the plugs are
now fouled. You'll need to either clean them or replace them
along with fixing whatever fouled them, so they don't just foul
again.
Bob
In article <dYTDa.109$oD6....@news.on.tac.net>,
sonodude
Thanks for your reply. If this were the case, why does the engine run fine
when I disconnect the temperature sensor? Its ONLY when the temp sensor is
connected that the car runs rough (low unsteady idle, poor accel., black
smoke out the pipe).
BTW, when the temp sensor is disconnected, the idle climbs to about 1300
rpm. My mechanic says this is the default setting when the sensor is
unplugged.
Gus
"Bob Hetzel" <b...@blackout.DMS.cwru.edu> wrote in message
news:bbqbik$cpc$1...@blackout.DMS.cwru.edu...
Bob Hetzel
mode (open loop). Since this seems to fix the problem on your end,
it means the computer is having a problem in closed loop (warm running)
aka feedback mode. The computer isn't dealing properly with a problem
in the feedback system. Could be the oxygen sensor, could be the coolant
temp sensor, could be any of the wiring involved in either. Could also
be the coolant, but if you scan back through this newsgroup using
www.dejanews.com you'll see more info.
But like I said, if it ran lousy for more than a few minutes the plugs
are fouled and you're not going to get it to run right with fouled plugs
even if you fix what fouled them.
Blaming parts hasn't helped you so far, and neither has the mechanic
who's been oh so willing to swap parts w/o zeroing in on anything.
So my first suggestion is to pick up a Bentley manual and give the
diagnostic stuff in there a try, or find a new mechanic. He may be
great on other cars most of the time but that shouldn't matter if he
can't fix the one you bring to him...
Surprisingly, these magical diagnostic steps are all in the Bentley
manual you can get for $10 on ebay or a used bookstore, or from $40
from your VW dealer. But most mechanics that don't specialize in VW's
don't use it or bother getting access to it, I suspect because they
would need a rather large storage room to accomodate all the manuals if
they started buying them for every customer's car...
Bob
In article <mT2Ea.111$oD6....@news.on.tac.net>,
sonodude
warranty) in the last six months; the current one is a week old. The O2
sensor was replaced end of february (the car failed one parameter of the
emmissions test, which the new O2 sensor did the trick). My mechanic has
checked the wiring and that seems to be OK.
My mechanic only works on euro imports (VW, BMW, Benz, Porsche, Volvo, etc)
and has been great up until this problem. Alot of that other stuff I
mentioned had to be replaced for other reasons, like the emmissions test (we
have to have these done in Ontario). I only mentioned them to avoid other
poster from asking " well, have you tried this . . . " etc.
I will ask him if he has the Bentley manual. I will also go through
dejanews.
Thanks again. You've been a great help.
Gus
"Bob Hetzel" <b...@blackout.DMS.cwru.edu> wrote in message
news:bbqjep$cqa$1...@blackout.DMS.cwru.edu...
sonodude
even if the plugs are fouled up right now, the can engine run fine when the
temp sensor is disconnected, yet run rough as soon as the sensor is
reconnected?
"Bob Hetzel" <b...@blackout.DMS.cwru.edu> wrote in message
news:bbqjep$cqa$1...@blackout.DMS.cwru.edu...
Bob Hetzel
which fouled the plugs so bad they were covered in black soot after
15 mins of idling. I could start the car when cold but it would stall out
after getting hot and wouldn't restart. But a few hours later it would
start again just fine.
This is way worse if you've got digifant and regular or Plus 4 Bosche
Platinums. There's so little surface area that if you're engine isn't
running well they foul fairly quickly. Get the stock Bosche silber
or copper ones if you wind up replacing them. Most regular auto parts
places don't sell them so you'll have to shop around your area or
get them online...
Bob
In article <t%4Ea.114$oD6....@news.on.tac.net>,
sonodude
couple of plugs and there soft carbon deposits on them, although not that
much (from what I can tell). I should also mention that in between my 5000
km oil changes, I have to add a least 2 litres of motor oil. This has been
the case for at least 3-4 years now. BUT, when running well, the exhaust is
clean (ie no blue smoke) , my garage floor under my car is clean and I
passed my last emmissions test.
That said though, I did notice a couple of times in the last month that my
exhaust did look a little blue-ish; one time after a 2 hour highway drive.
But it cleared up the next time I drove.
If I was burning oil, wouldn't I see blue exhaust all the time? Or can it
be intermitent, even sparingly? Should I pour some of that "stop leak"
stuff you pour into your oil?
"Bob Hetzel" <b...@blackout.DMS.cwru.edu> wrote in message
news:bbqns5$cr3$1...@blackout.DMS.cwru.edu...
Bernd Felsche
>Many thanks Bob! The coolant temp sensor has been replaced 3 times
>(under warranty) in the last six months; the current one is a week
>old. The O2 sensor was replaced end of february (the car failed
>one parameter of the emmissions test, which the new O2 sensor did
>the trick). My mechanic has checked the wiring and that seems to
>be OK.
Check the chassis ground connection (braid) at the corner of the
cylinder head. If that's intermittent or simply bad, then it can
lead to a The lambda (O2) sensor burning out very quickly and might
lead to a permanent ECU failure.
Disconnect the sensor next time the engine runs rough.
Of course - turn off the engine first... disconnect, then restart.
If rough running, etc doesn't recur, then it's a sensor fault.
>My mechanic only works on euro imports (VW, BMW, Benz, Porsche,
>Volvo, etc) and has been great up until this problem. Alot of that
>other stuff I mentioned had to be replaced for other reasons, like
>the emmissions test (we have to have these done in Ontario). I
>only mentioned them to avoid other poster from asking " well, have
>you tried this . . . " etc.
1300 rpm is far too fast an idle, btw. even with the coolant
temperature sensor disconnected.
Once you've fixed the closed-loop engine management, go over all the
basic settings for ignition and idle speed; and check lambda and
knock according to the Bentley manual.
No point taking short-cuts.
My otherwise competent VW specialist mechanic took months to identify
a basic timing problem after a cylinder head overhaul. His
sub-contractor has reversed the cam sprocket so the timing marks
used for assembly weren't the correct timing marks. The mechanic did
blame the ECU until the time he put a straight-edge across the cam
lobes.
--
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Matt B.
news:T_MDa.108$oD6....@news.on.tac.net...
Never recalled that I know of.
John
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33596
&item=2417847386
John
be the cause of these symptoms? The reason I ask is that after replacing a
radiator and refilling with prestone at 50/50 I am suddenly having stalling
problems . I even went went so far as to buy a used computer without any
success.
john
> From: b...@blackout.DMS.cwru.edu (Bob Hetzel)
> Organization: A poorly-installed InterNetNews site
> Newsgroups:
> rec.autos.makers.vw.watercooled,rec.auto.vw,rec.autos.makers.vw,rec.autos.vw
> Date: 6 Jun 2003 13:36:25 -0400
> Subject: Re: Recall question, 1991 Jetta, computer
>