Date: Sat, 17 May 2008 00:03:27 -0700
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: hesitation/bucking (was: Re: tested Oxygen Sensor, and...)
In-Reply-To: <91c8f9760805162306t6a2165f3q885a26392bf39e09@mail.gmail.com>
Content-Type: text/plain; charset="us-ascii"
If moisture is a factor in how an engine runs.......
Normally you think of ground connectins, spark plug wires and so
forth.....anything associated with electrons.
Btw way, on my list of 30 to 50 things to check to make a waterboxer engine
run right........is the fuel itself.
Hardly anyone ever considers the fuel itself that I know of, not even pro
shops.
A couple of months ago - there was a 1.9 waterboxer vanagon here that must
have had half a gallon of water in the fuel tank.
But where moisture makes it run better or worse - you think about electrons
usually, and if they flow where they should, and don't leak where they
shouldn't , generally speaking.
Scott
www.turbvans
vanagon specialist and vanagon engine conversion specialist.
More...........
And with a properly really well running good Subaru engine in there.....
One that holds a set up and a tune nearly indefinitely - and some of them
do, especially the early 2.2's with a really sold conversions ......if you
had one of those for a few years,
And got better mileage, way more throttle response, more power and another
1,000 rpm to play with, in retrospect you would just laugh about waterboxer
engines. Just laugh and laugh and say why are you messing with that
converted air-cooled design with early 890's technology ?
No comparison baby.
And a vanagon is SO worthy of more modern engines. The systems in the decade
and half newer tech of a Subaru engine are......... no kidding, twice as
strong and twice as accurate.
A waterboxer engine doesn't even have a crank or cam position sensor.
The ECU does not really know where the engine is, just that it's turning -
via the distributor. The turning distributor is the only way a waterboxer
ECU knows the engine is turning. It knows rpm of course, but not crank and
cam positions. Not very accurate.
The fuel injection on a waterboxer is not sequential - the ecu just fires
the 4 injectors as one big injector.
Subaru is sequential of course.
An SVX engine has two crank position sensors ( not cheap either, but you
almost never need one ) and one crank position sensor,3 sensors telling the
ECU exactly where the engine is . And knock sensor ignition so it can't
ping, and you never set timing - timing control is fully integrated into
the ECU, and there is no distributor to wear out - another place electrons
and something mechanical meet - a weak area - Subaru's just don't have
that part..........and 4 valves per cylinder and a big swoopy intake
manifold.......really, here we are driving our Vanagons in the 2000's with a
early an 80's tech waterboxer pushrod engine ( that have joke 'head
gaskets' ) ...............when you move up to a 90's era Japanese engine
...........there is just no comparison, baby, just none at all. Can be
expensive yes, - conversions , but the vans are worthy of it. A good
running 6,000 rpm 4 cylinder Soobie engine, is just ORGASMIC to drive in a
good vanagon.
And there are other good modern engines to fit into them of course.
I'm partial to the similarity of the opposed four aluminum engine - that
was the original spec from when they invented the VW bus in 1948 or
whatever, all the way up to 1991 Vanagon - rear mounted, opposed aluminum 4
cylinder engine. It matches the original concept just perfectly, and looks
like it was meant to be in the engine bay too. Could not fit better.
And once dialed in well with a solid conversion job ............you don't
even work on them much often after that, not the ones I build anyway. Takes
me a LONG time to get them nigh perfect sometimes too.
On the other hand, I've fired up a new conversion......
And there was not ONE issue, from the first time I fired it off.
People ask me if they are easy to work on in the vanagon - two thoughts -
one it is WAY easier to work on the Subaru engine in the vanagon than in the
original Subaru car ........and.....once dialed in really right - you don't
work on them much quite often.
They can be so smooth you have to look at the tach to see if they are
running at idle.
I think I made my point ! lol !
Scott
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
pickle vanagon
Sent: Friday, May 16, 2008 11:07 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: hesitation/bucking (was: Re: tested Oxygen Sensor, and...)
Just to add to what I already wrote.
It sounds like this old post (the response part) is describing my problem
exactly (except the part about not having it for several thousand miles):
http://gerry.vanagon.com/cgi-bin/wa.exe?A2=ind9605&L=vanagon&D=0&P=145769
I didn't think of it before, but now that I read it in his description, it
seems to me that most times I have noticed the problem it has been wet
outside (for example, today!). This could be a coincidence, though, I
guess.
Thanks again for any help!
Wes
On Sat, May 17, 2008 at 1:47 AM, pickle vanagon <greenvanagon@gmail.com>
wrote:
> Thanks for all of the responses, guys.
>
> I think maybe the first time I hadn't let the van heat up enough. (The
> engine was already warm, but maybe I didn't actually let the sensor heat
up
> enough?)
>
> When I measured again, I did get fluctuation, but the swing wasn't as
large
> as .5volts. I'd say ut swung between around .4 and .7. I guess its
> possible that there was actually a greater swing than was showing up on my
> digital voltmeter. I should mention: the oxygen sensor is only about 4000
> miles old.
>
> Anyways, the reason I was checking the oxygen sensor voltage in the first
> place, is that I've noticed recently (since my head job...) that the van
> occasionally exhibits some slight hesitation symptoms when driving at a
> constant speed (usually low speed, so low load). The van surges slightly
> forward and back, maybe at a rate of once per second or so, kind of like
> very minor bucking. It only has happened occasionally, so I can't say for
> sure when it seems to happen the most. But it has never happened when
> accelerating or otherwise when under load, and it has never caused any
> problems idling. It idles very smoothly, although it seems to me that
it's
> idling at lower rpms than before. Of course I don't have a tach so I
can't
> say for sure.
>
> What should I look for with these symptoms? The only things I've done
are:
> looked around for any obvious vacuum leaks, checked the oxygen sensor as
> above, rechecked my valve adjustment, checked my Temp 2 sensor, and
replaced
> the engine compartment ground strap (the one that goes to the head). I'm
> guessing that with a problem like this, there's a list of 50 things to
> check.
>
> I guess I should really be checking the mixture properly in a situation
> like this, but I don't have an co meter or anything for the exhaust.
>
> Thanks for any pointers,
> Wes
> 1.9l westy
>
> On Fri, May 16, 2008 at 11:25 PM, Dennis Haynes <d23haynes57@hotmail.com>
> wrote:
>
>> A steady reading of .5 to .6 volt is a sign of an open sensor or one that
>> has not heated up enough to function. The voltage is due to the leakage
at
>> the ECU input. Measure the voltage at the sensor lead with it
disconnected
>> to see if you are really getting a signal.
>>
>> Dennis
>>
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>> Of
>> pickle vanagon
>> Sent: Friday, May 16, 2008 5:53 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: tested Oxygen Sensor, and...
>>
>> Just for fun, I decided to go out and "test" my oxygen sensor today, by
>> which I mean I warmed up the car, and then checked the voltage coming off
>> the sensor wire with the van at idle. I got readings of around .52
volts,
>> which maybe seems okay (?), but the voltage was steady, not oscillating
>> (it
>> stayed between .51 and .53 volts always). Does this mean my engine is
>> never
>> entering closed loop operation? If so, what are the standard things to
>> check, since the O2 sensor seems okay?
>>
>> Thanks,
>> Wes
>>
>
>
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