Date: Sun, 16 Jan 2005 18:37:50 -0600
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: capacitor fix mitigated buck, did not fix
In-Reply-To: <41EA90EA.15916.16AF6CFD@localhost>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Use to be that Darryl Boehler would reflow the solder in an ECU when he
was buildin up a a Boehler Dii-tool. He did that to ensure that when
you bought a complete setup from him - the digitool and the ECU - that
the ECU would work properly. He use to, as I recall, encourage the
purchase of the ECU from him so you would have a good one that he had
checked out, and you would have the old one as a spare. And everybody
needs a spare ECU.
As for the bucking. My 88 GL did the bucking thing. I found the problem
to be the hose from the crankcase vent to the AFM. That hose had rotted
on the bottom and had a hole in it. It is a problem easy to miss. I
replaced the hose in the parking lot of my FLAPS - no more bucking as I
drove home.
John Rodgers
88 GL Driver
Shawn Wright wrote:
>I had similar symptoms, and the capacitor fix seemd to help a little also. After
>capacitor fix, extra grounds, adjusting AFM wiper arm, etc, my problem was
>eventually cured completely by examing the ECU - I found several cracked solder
>joints. Heated & re-flowed the solder, and all has been great for 2 years now. I don't
>know how common this is, but it is fairly simple to check for. Use standard
>precautions when working with ECU re: static electricity of course. (mine is an '88
>also).
>
>On 16 Jan 2005 at 16:11, Warren Lail <wlail@OU.EDU> wrote:
>
>
>
>>Hi all,
>>
>>Maggie and I made a safe and fun trip to New Mexico (1200 miles roundtrip) and
>>Bill Bones performed well, sort of...
>>
>>The dreaded bucking syndrome began so I stopped and soldered in a 15 volt 22
>>microfarrad tantalum capacitor that I got from listmember Tom Miller. I
>>connected the positive side to number 2 and the negative side to number 4.
>>Interestingly, the idle that had always surged, was now stabilized. The next 50
>>miles were a joy. No bucking at all.
>>
>>However, after about an hour on the road, just when the bucking normally begins,
>>I got a diluted version of the same thing. It appears that the capacitor stores
>>energy or something like that, and when the system needs it it is returned (not
>>sure about this). The result was that instead of a bucking jolt like I normally
>>get, I got a slow loss of power, and then a return surge. It is as if the
>>capacitor is almost powerful enough to remedy the situation, but not quite.
>>
>>On the return trip, I got behind the bus and smelled the exhaust. It seemed to
>>have that smell associated with a lean engine. Not wanting to burn anything up,
>>I disconnected the capacitor.
>>
>>Of course, the original bucking returned, as did the high idle (1800 rpm after
>>coming off the Interstate). The high idle is never a problem around town. It
>>only occurs after extended driving on the Interstate, and accompanies the
>>bucking behavior.
>>
>>Several questions:
>>
>>1. Is the capacitor really a fix or just a band-aid?
>>2. If it is a fix, what did I do wrong? If a band-aid, what is the real cause
>>and how can it be remedied? 3. Will a new AFM solve the problem? 4. Is the
>>factory pigtail a better fix (albeit a more expensive one)?
>>
>>As always, thanks for your help.
>>
>>Warren Lail
>>88 Westy "Billy Bones"
>>
>>
>>
>
>--
>Shawn Wright
>I.T. Manager
>Shawnigan Lake School
>
>
>
>
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