Remember that if the idle speed exceeds 1400 rpm when engine in warm, the
ECU cuts off the fuel until the idle speed drops back.

John
----- Original Message -----
From: "Jonce Fancher" <streetbugs@WHISPLLC.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, April 09, 2006 4:10 PM
Subject: Re: digijet FI adjustments

> Hi Brian
> I also have a 84 that will run like a dream but when it warms up it will
> go into as small surging at idle after a freeway run. if i just sit there
> at idle it just stops
> surging. i then do another run of some sort and it surges but after about
> a half a min it goes away. it does not affect throttle response or power
> or anything. It
> is just a pain to pull up to the light and it just surges or small revs. I
> did pull a vacuum line off of the air distributor just to check something
> and the surgind
> started right up. so My guess is i have and you may have a air leak after
> the throttle body. A friend of mine did have a rusted out seam on the
> bottom of his
> air distributor a few years ago.  My van is still surging and ive yet to
> find the source. Of cours one of the push rod tubes has just started to
> leak so i will be
> fixing this soon. This van only has 23 k on it since new but ive replaced
> most all rubber items on it due to age. Let me know if you find the issue
> if not an air
> leak. thanks Jonce
>
>>Dennis or anyone,
>
>>I found this thread in the archives. It describes the situation with my 84
>>1.9 digijet.
>
>>I occasionally have surging at idle, especially immediately after a warm
>>start.  How can I correct that?
>
>>Unplugging the O2 sensor and/or the idle stabilizer doesn't stop the
>>surging. I have set the throttle idle switch, timing and idle speed as per
>>the Bentley. The Temp II sensor was replaced a couple years ago, as well
>>as the grounds being checked (but I couldn't find one on the right-side
>>head). It was running great without this surging until I had to reseal the
>>heads a couple of months ago.  The surging started after that job was
>>complete.  I can't find any connectors that I missed, and I'm almost
>>certain all the vacuum lines ended up in the correct places. I might have
>>a vacuum leak somewhere near the throttle body. I can't tell if it really
>>is a leak, or if it is just air whooshing through the throttle opening.
>>Today I tried simply screwing in the idle adjustment screw until the
>>surging subsided. I haven't tried yet to drive it or to start it cold with
>>this new idle setting.
>
>>The van is performing great otherwise, so I haven't worried too much about
>>fixing this. Should I worry?
>
>>Thanks for any advice,
>
>>Brian
>
>
>>On Mon, 11 Oct 2004 08:32:19 -0400, Dennis Haynes <dhaynes@OPTONLINE.NET>
>>wrote:
>
>>>If you have the Bentley and a good Digital volt-meter and a timing light
>>you can do it. The Digijet requires very specific set up for the throttle
>>plate, ignition timing, idle speed and CO. The adjustment on the AFM is
>>only to help trim the adjustment at idle. Basic setting are as follows:
>>>
>>>Engine close to operating temp.
>>>With engine off, disconnect 02 sensor and bypass idle stabilizer.
>>>Check throttle plate adjustment. Adjust stop screw so it does not stick
>>closed. Idle air goes through bypass screw. Check operation of throttle
>>switch or switches. Adjust as needed.
>>>Start engine, adjust timing to proper mark at idle speed. Check vacuum
>>advance operation. Opening throttle should quickly advance timing. Further
>>check, remove vacuum retard hose, (one directly to manifold). Timing must
>>advance. If not, hoses are wrong, diaphram is bad, or throttle plate not
>>adjusted properly. Find cause. Adjust idle speed to ~950 rpm.
>>>Using voltmeter, check O2 sensor voltage, (still disconnected). Should be
>>about .5v. If no reading, rev engine for 30 seconds to heat sensor. Adjust
>>AFM to get .5v. Just get it close. Slightly lean is better. Adjust idle
>>speed again if needed.
>>>Shut off engine, reconnect stabilizer and O2 sensor. Restart, and check
>>O2 sensor operation. After 30 seconds or so, you should be able to see it
>>working.
>>>
>>>On occasion, you may have surging at idle, especially after a warm
>>restart. If you do, I'll tell you how to correct that.
>>>
>>>Dennis
>>>
>>>
>>>
>>>----- Original Message -----
>>>From: Darren Lastfogel <dlastfogel@PLYFORMS.COM>
>>>Date: Monday, October 11, 2004 7:40 am
>>>Subject: Re: digijet FI adjustments
>>>
>>>> Ok I replaced the O2 Sensor, temp 2 sensor, checked fuel pressure
>>>> 32 psi,
>>>> adjusted RPMs to about 900 and checked all vacuum connections, now
>>>> it runs
>>>> fine after warm up(stalls when cold)Still runs rich, but better.
>>>> Back to the
>>>> CO adjustment screw Bentley just says adjust. Adjust to what? is
>>>> it in for
>>>> lean? or out for lean? or should I leave it to a mechanic? I was
>>>> thinking of
>>>> buying the JCW fuel ratio gauge to monitor.
>>>>
>>>> -----Original Message-----
>>>> From: dhaynes@optonline.net [dhaynes@optonline.net]
>>>> Sent: Friday, October 08, 2004 8:59 AM
>>>> To: Darren Lastfogel
>>>> Cc: vanagon@GERRY.VANAGON.COM
>>>> Subject: Re: digijet FI adjustments
>>>>
>>>>
>>>> This is not an adjustment problem, something is wrong. Most likely
>>>> culpritis the temp 2 sensor or the connection to it. Check ground
>>>> connections etc.
>>>> Rich running after warm is probably bad O2 sensor.
>>>>
>>>> Dennis
>>>>
>>>> ----- Original Message -----
>>>> From: Darren Lastfogel <dlastfogel@PLYFORMS.COM>
>>>> Date: Friday, October 8, 2004 7:18 am
>>>> Subject: digijet FI adjustments
>>>>
>>>> > Good morning Listees
>>>> >
>>>> > Last night I installed new exhaust gaskets because the PO never
>>>> > put any on,
>>>> > It always ran fine just sounded bad. Now it sounds quiet. This
>>>> > morning I was
>>>> > on the way to work and it was running very rich then after I turn
>>>> > it off I
>>>> > could not get the engine to start. My question is where do I
>>>> > adjust the air
>>>> > to fuel so the engine will lean out? and where is a good starting
>>>> > point?
>>>> > Darren
>>>> >
>>>>
>
>
>>--
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>
>
>
> Jonce Fancher
>
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> 85 Vanagon Westi
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>
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