Date: Mon, 2 Feb 2015 14:01:32 -0700
Reply-To: Jon VO <jondvo@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jon VO <jondvo@GMAIL.COM>
Subject: Re: Removing stuck O2 sensor
In-Reply-To: <CAHTkEuJeauFfk-CuAtQ977rV=Dh23kd8UduGhFURgfZD8_wUHQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
The Digifant system worked fine in the 90's. Now these systems are very
old and one should expect some issues. Engine sensors in general have
improved in resolution, durability, and cost, and the newer systems have
a few improvements. One sensor that Digifant doesn' t have is knock
sensing, and this coupled with more sophisticated ignition, fuel
delivery, and valve timing control, results in more efficient and
powerful motors, while enhancing drivability. The VW motor is fine, and
I have had good results from all of mine, but I would like to see an
improved engine management system, if it was not too $$. After all,
Digifant is 20+ years old.
Jon
On 2/2/2015 1:29 PM, Don Hanson wrote:
> Dunno about YOUR Digifant, but mine seems to be just fine on the ABA hybrid
> inline...Seems like I hear all kinds of stories of problems with trying to
> change over to some other ems, and certainly that seems the case with
> Subaru conversations, unless the owner has paid someone big dollars to do
> it all for them.
> Maybe I'm just an exception, but after reading all I could find on the
> other VW systems I decided there was NO advantage to change from
> Digifant.. None. But....as they say, "it's more modern, newer
> technology... It HAS to be better".
>
> On Feb 2, 2015 10:46 AM, "Stuart MacMillan" <stuartmacm@gmail.com> wrote:
>
>> It's really more of a low idle when cold that causes off-idle stumble for
>> the first few minutes. I set the idle to 850 and it comes up 50-100 rpm
>> when the ICU is plugged back in, and then lopes +- 100 rpm. All grounds
>> have been checked and cleaned, and the T2 socket is good (this is a rust
>> free California/Oregon van). Only original parts are the idle control valve
>> (which hums, but not all the time, should it?), PCV valve (could that cause
>> the problem?), and the Hall sender.
>>
>> I've installed rebuilt injectors, as well as a used ICU (original had a
>> burned component), Temp 2 sensor, adjusted the TB switch & cleaned the TB,
>> fuel pump and filter, all new tune up parts, but carbon on the intake
>> valves
>> is a possibility. We will be running top tier gas and see what happens, or
>> we may just have to live with it.
>>
>> After a great experience with a rebuilt 2.1 upgrade in my '84 15 years ago,
>> I wish I could just replace all this unnecessary complication with the
>> 1.9's
>> Digijet injection system until we can do a Subaru conversion.
>>
>> The Digifant system is just an overly complicated attempt at keeping an
>> obsolete and inefficient engine in production for too long.
>>
>> Stuart
>>
>> -----Original Message-----
>> From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
>> Sent: Sunday, February 01, 2015 9:23 PM
>> To: 'Stuart MacMillan'; vanagon@GERRY.VANAGON.COM
>> Subject: RE: Removing stuck O2 sensor
>>
>> For the stumble when cold you need to look at the injectors for spray
>> pattern and check for excessive deposits on the intake valves and possibly
>> worn intake guides. For the idle hunt this is sometimes common. What is the
>> idle speed with the idle valve unplugged? This should be about 800 on a
>> warm
>> engine. The idle valve needs to always provide some boost to be ultimate
>> control. Normally they shoot for somewhere between 850-950 rpm. For the
>> temp 2 sensor I find that many of the aftermarket ones are not quit right
>> and bad ones come in batches. The OEM ones rarely go bad. Most of the time
>> problems with this circuit are due to the connector or the wiring near it.
>> A
>> bad ground on this circuit creates a lot of havoc as it is shared with the
>> ECU and idle speed controller.
>>
>> Dennis
>>
>> -----Original Message-----
>> From: Stuart MacMillan [mailto:stuartmacm@gmail.com]
>> Sent: Sunday, February 1, 2015 11:04 PM
>> To: 'Dennis Haynes'; vanagon@GERRY.VANAGON.COM
>> Subject: RE: Removing stuck O2 sensor
>>
>> Well, maybe I will leave it as is, this van is exempt from testing. I
>> still
>> have a cold running stumble, and a slight idle surging when warm (900-1000,
>> up and down) after the temp 2 sensor replacement. I'm pretty much out of
>> options now, but I'll look for a vacuum leak before I turn it over to a
>> shop.
>>
>> Stuart
>>
>> -----Original Message-----
>> From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
>> Sent: Sunday, February 01, 2015 5:47 PM
>> To: 'Stuart MacMillan'; vanagon@GERRY.VANAGON.COM
>> Subject: RE: Removing stuck O2 sensor
>>
>> It's not the lift, but having the oxy acetylene torch and knowing how to
>> use
>> it. I last wasted money on the Map gas torch some 25 years ago. It is
>> really
>> limited to brazing soft materials. Need to get steel red hot fast, your
>> need
>> the real deal. Must be nice to live in an area where a shop will remove a
>> catalyst. Without the cat you may not need the O2 sensor. The O2 sensor is
>> there to make the cat do its job.
>>
>> Dennis
>>
>>
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>> Stuart MacMillan
>> Sent: Sunday, February 1, 2015 1:50 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Removing stuck O2 sensor
>>
>> You can do that because you have a lift! I've given up. Tried MAP gas with
>> an O2 sensor crow's foot tool and could only get it 1/8th turn. At least
>> NAPA loans those tools, but 7/8" is too big, and rounded the corners.
>>
>> If the treads are buggered, the shop can replace the cat with a pipe &
>> bung,
>> I don't need it.
>>
>> Stuart
>>
>> -----Original Message-----
>> From: Karl Wolz [mailto:wolzphoto@q.com]
>> Sent: Sunday, February 01, 2015 12:23 AM
>> To: Stuart MacMillan
>> Cc: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Removing stuck O2 sensor
>>
>> I use a Stilson wrench and a four foot heavy pipe as a cheater.
>>
>> Karl Wolz
>> Sent from my electronic umbilicus
>>
>>> On Jan 31, 2015, at 11:59 AM, Stuart MacMillan <stuartmacm@GMAIL.COM>
>> wrote:
>>> Well, first attempts with a 22mm box wrench and heat have failed.
>>> Should I break it off and use a regular 22mm socket? Get a 7/8"
>>> special O2 sensor socket, which is slightly larger, so I can put a
>>> long bar on it? Take it
>> to
>>> a muffler shop?
>>>
>>>
>>>
>>> Other ideas?
>>>
>>>
>>>
>>> Thanks!
>>>
>>>
>>>
>>> Stuart
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