Date:         Sun, 21 May 2017 12:24:41 -0700
Reply-To:     Wes Neuenschwander <wes.neuenschwander@COMCAST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Wes Neuenschwander <wes.neuenschwander@COMCAST.NET>
Subject:      Re: Intermittent Power Loss - '91 Westy
In-Reply-To:  <CANEuo0go1h5MxyjtzQ7Jt33Prc3NvNrVsbHWR+XQPCm2FRamxQ@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hi Ken!

 

Many, many thanks for the info and suggestions.  I am a veritable Vanagon idiot, relying on shops and folks like you to help me keep on Vanagon-ing, but what you said below makes perfect sense to me.  (And while I'm Vanagon illiterate, I was a pretty decent mechanical engineer, specializing in control systems; so I'm fairly decent at understanding technical stuff in general.)

 

FWIW, I've been driving the van daily since we disconnected the O2 last Monday, mainly short trips, with multiple starts and stops with absolutely no problems.  Given that the incidence of failures before was so low (twice), this isn't conclusive, but would appear to suggest the O2 sensor itself might be to blame.

 

Personally, since I'm not Vanagon savvy – and am risk averse – I'm inclined to be proactive and replace the more likely culprits, which at this point would seem to be the O2 sensor for sure and perhaps the O2 sensor wiring, as well perhaps the ECU (original equipment) and the Hall sender (if it hasn't been replaced;  I'll have to check my records).  Chris (my local Vanagon guru) has also suggested perhaps replacing the O2 wiring, as he's found shorts in other vans and not just near the connector.  

 

BTW, do you do the rebuilds on the ECU's yourself and what's the extent of the rebuild (just resoldering or do you replace components)?

 

-Wes

Seattle, WA

 

From: kenneth wilford [mailto:kenwilfy@gmail.com] 
Sent: Sunday, May 21, 2017 5:44 AM
To: Wes Neuenschwander; Vanagon List
Subject: Re: Intermittent Power Loss - '91 Westy

 

If it is the oxygen sensor wiring there is an easy way to tell for sure.  When the van is running poorly, turn the ignition off and then back on again.  If you are driving down the road, you do not need to engage the starter, the van will instantly restart.  Does the van run better for 30 seconds before running poorly again?  If yes then 100% it is related to the oxygen sensor wiring.  The computer looks at all of the sensors immediately when you start the van except for the oxygen sensor which is on a time delay.

 

If it is not the oxygen sensor wiring then ECU is the first suspect with hall sender in distributor being second.  If they have never been replaced, I would preemptively replace them both as it is time.  

 

Of course we sell both of these items at vanagain.com.  ECU is $250 and hall sender is $149.  Let me know what you find out.

Ken Wilford at vanagain.com

 

On May 20, 2017 1:48 PM, "Wes Neuenschwander" <wes.neuenschwander@comcast.net> wrote:

While preparing our 'trusty' '91 Westy for a trip to the remote (and
supremely lovely) Okanogan region of Eastern Washington, I experienced a
sudden loss of power, with the rpm's dropping from 3,000 to around 800, even
with the throttle depressed.  Still on my local Seattle neighborhood
streets, I pulled over and after a minute or so was able to nurse the engine
back up to 3,000 rpm, restoring power and driving back home.  Took it
directly to my regular (and every excellent) local VW shop, Fine Tuning in
N. Seattle, without any power loss or other problems.   The car repeated the
power loss during a test drive, this time losing power completely and engine
dying.  The owner, Chris, was able to restart the engine after a couple of
minutes and got it back to the shop, where they went over the obvious stuff,
not finding anything.  Next day, they started the vehicle and left it idling
for an hour or so, without problems.  Subsequent test drives also went
without problems.



On Chris' suggestion we disconnected the O2 sensor and I've been driving it,
mainly on short, local drives now for several days without incident.



Haven't encountered anything similar in the 26 years we've owned the van
(bought it new in '91), though have barely driven it for the last couple of
years (like 700 miles over 2 years!) with the van sitting in the garage,
idle, for the last several months or so.



In addition to the O2 sensor / sensor wiring possibility, Chris has also
suggested it could also be a faulty ECU.  The ECU is original, and I know
these tend to have solder joint corrosion problems over time.  I'm not sure
how old the O2 sensor might be, though it's probably not original (but I
suspect it's pretty old).  Ditto, I guess to a degree, various other
sensors, as well as sensor wiring.  Ignition components, including spark
plug wiring, distributor, etc. have been fairly recently been replaced.



The engine is a GoWesty 2.2L engine, installed nearly 10 years/25,000 miles
ago, and aside from the recent loss of power problems, has run beautifully
since it was installed.



I've done a lot of searching of the Vanagon List archives for information
about similar loss of power problems, so realize the O2 sensor and ECU
issues are commonly involved in such situations, but would be most grateful
for any/all ideas or suggestions for other things to check.  At this point
I'm more than willing to invest in a replacement O2 sensor and even (if it
seems indicated) a rebuilt ECU.  However until something is found that
reasonably explains these random power loss events I'm very reluctant to
drive the van very far and certainly not into remote areas.



Many thanks (as always)!



-Wes

___________________

Wes Neuenschwander

wes.neuenschwander@comcast.net

C. 206.498.8787