Date: Tue, 5 Oct 1999 22:38:17 -0400
Reply-To: John Lauterbach <jhlauterbach@EMAIL.MSN.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Lauterbach <jhlauterbach@EMAIL.MSN.COM>
Organization: Microsoft Corporation
Subject: Re: 1/4 mile syndrome is back!
Darie, I have had a similar problem with my '84DL. In my case, I have (with
the help of my mechanic) to the connector between the ECU and the FI wiring
harness. If these contacts are anything but squeaky clean, I have problems.
Last week, I had problems restarting van after a short drive. If I went
back to the engine, wiggled the connector a couple of times, it would start
right up. No wiggle, no start.
John in Middle Georgia
'84DL
----- Original Message -----
From: Darie Duclos <Darie.Duclos@UNIFR.CH>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, October 04, 1999 10:03 AM
Subject: 1/4 mile syndrome is back!
> Help!
>
> I thought this problem had gone away, but now that I've got
> road inspection this week, it turns out it's not solved. I
> have a pretty good description of the symptoms now. Perhaps
> you can help me narrow down the possibilities.
>
> The problem: accelerator pedal begins to have little or no
> effect on propelling the vehicle forward. When the speed
> has dropped sufficiently, the engine hiccups forward, as
> if I wasn't giving enough gas. The RPMs go down, so it's not
> something like the clutch slipping. It may feel like it's
> running of fewer cylinders. Without even stopping, I can
> turn off the ignition and right back on, and the acceleration
> is back for 1/4 to a 1/2 mile, then the same thing happens
> again.
>
> Important details:
> - when engine is cold, no problem, I can start it up and
> drive with no apparent time limit so long as I don't turn
> it off.
>
> - each time (3 or 4 times) the engine was running between
> 10 and 30 minutes, then *was cut and started again* (with or
> without much of a pause), the problem occurred: I had to
> cut the ignition and restart every 1/4 mile until my
> destination.
>
> - after a *45* minute drive (from cold start of course),
> cutting the engine and starting again several times, with
> varying delays, did *not* reproduce the problem.
>
> - arg! I just tried to reproduce the problem again by driving
> 5 minutes and shutting off the engine, then restarting.
> It won't do it! It only does it when I really want to
> go somewhere!! Damn piece of merde.
>
> - the engine is running much too rich. (At least) when it has
> the problem, it spits out coal, enough to make a serious
> black stain on the pavement or on your pants if you're standing
> behind the bus.
>
> - a car electrician just checked some values related to the
> temperature sensor. He found that at 40 degrees it read
> 1200 somethings (ohms? I can't remember) but he couldn't
> find my model of bus in his references and he didn't know
> for sure whether this value was normal. I left him my
> Haynes manual but I don't know if it's in there. Anybody
> know what this value means and what it should be for an
> 86 2.1 liter water-cooled vanagon (MV)?
>
> The only thing for sure about this problem is that it has never
> occurred on a first run after cold start. It has only happened
> upon starting up the engine when already warm. And then, if it
> starts doing it, it does it at every startup. If it doesn't do it,
> it doesn't do it at all no matter how many times I restart.
> The following possible causes had been
> suggested after my previous postings. I would like some opinions
> about which could be ruled out because I have very little time
> until the inspection and I'm afraid that if I take it to a garage
> it will cost me an arm and a leg before they even figure out what's
> wrong.
>
> - fuel pressure (pump or regulator)
> I changed the fuel filter with no effect. How can I test the
> pump or regulator?
> Wouldn't this cause a problem upon a cold startup or during
> an initial run?
>
> - bad O2 sensor
> We disconnected and reconnected the O2 sensor once, before the
> 45 minute test drive, to see how the bus ran. Then we tried to
> reproduce the problem with the intention of disconnecting the
> O2 sensor at that time and see if the situation improved.
> Unfortunately, after driving 45 minutes, the problem did not
> occur.. I plan to try this after a shorter drive, but I'm not
> sure what I should expect. i.e. it's runs bad, I disconnect the
> O2 sensor, it runs better? Some of you said it wouldn't run very
> well with the O2 sensor disconnected so how do I tell the difference?
>
> - bad temp II sensor
> Would this not cause a problem even without cutting the engine,
> simply just when the motor gets warm?
> I can see how some of these things would get reset upon restarting
> the engine and I heard that their values are ignored by the
> "computer" for a little while after startup, but I don't see why
> they shouldn't affect the "first run" after the motor has gotten
> warm.
>
> - grounded O2 sensor circuit, loose or disconnected O2 sensor ground
> I may have twiddled it both times when the problem could not
> be reproduced. How could I check for sure that this is the
> cause? I guess the car electrician could do something with
> measurement instruments but I have to reproduce the damn problem
> for him, which I just failed to be able to do.
>
> - clogged catalytic converter
> Shouldn't the problem be more constant then?
>
> - faulty ignition switch
> Is it dependent on the warmth of the motor?
>
> - gas cap plugged up
> my gas cap is not ventilated, but maybe some other ventilation
> is plugged up. However, the pattern of the symptoms speaks
> against it again.
>
> If you can help me narrow down the possible causes, I would be
> very thankful. Also, if you can point me to the procedure for
> incriminating or innocenting one or the other component, that
> would be great.
>
> I'm kind of on my own (swf) to do this now since I moved out of
> the pretty-good-with-mechanics-boyfriend's place yesterday. I'm
> not very experienced but I can do anything I'm told. (Hey, I changed
> my pilot bearing a few years back with your help..) And I've got my
> Haynes manual..
>
> Thanks a bunch!
> Darie
> '86 multicolour canadian Westy with swiss landed immigrant status
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