Date: Mon, 10 Aug 2009 12:14:35 -0400
Reply-To: Robert Stewart <robertmstewart@MAC.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert Stewart <robertmstewart@MAC.COM>
Subject: Re: 1988 Rebuilt Engine Stumbling at various RPM levels
2100-2300, 3400- 4000rpms
In-Reply-To: <043601ca187d$266592d0$6501a8c0@PROSPERITY>
Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Is it all possible that what I am experiencing is due to a faulty Idle
control unit?
R
On Aug 8, 2009, at 7:08 PM, Scott Daniel - Turbovans wrote:
> I believe there are few resistance checks in the Bentley book for
> the AFM.
> Can't remember the last time I measured any though.
>
> it's common for the sweeper in the AFM to not make contact where
> it's been
> rubbing for 'ever.'
> there are tricks and tweaks to do there, and 'some progress' is
> possible...
> but a new or AFM is the right way to go if that's the
> source, of one of the reason it stumbles, or runs unevenly.
>
> 'mostly' AFM's make it run unevenly.
> I've seen them 'loose power' for a instant ......then recover, that
> was worn
> contacts in the AFM.
> I've seen a van that seemed to subtly 'miss' at 3,100 to 3,200
> rpm .....but
> it wasn't missing per se, it was a bad AFM.
> on that particular syncro, you were always right at about the rpm,
> in normal
> driving, like 80 % of the , seems you were right at that rpm.
> new AFM fixed that perfectly.
>
> it's usually worthwhile to do the checks and tests that are in the
> Bentley
> book , that you can do.
> Where they say plug in some special VW tool or instrument, you can't
> do
> that, but many of the checks are just continuity and resistance.
> Just start at the beginning in the fuel injection and ignition
> section etc,
> and do all those checks.
>
> It IS ..for sure, a 'blockage or leakage, of fluids and
> electrons" , and
> don't forget that 'fluids' include gases, not just liquids.....
> gases like vacuum, air, and exhaust .
>
> on page 28.42 they do mention checking timing with a timing
> light ...and
> say it should be on the notch.
> which is well known I'm sure.
> shoot me the link to those timing instruction you mentioned, if you
> can
> please,
> thanks,
> Scott
> it's not the timing, unless it's way off, or there's more to it than
> is
> obvious at first.
> Try not to be oblivious to the obvious of course !
>
>
>
> ----- Original Message -----
> From: "Robert Stewart" <robertmstewart@MAC.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Saturday, August 08, 2009 2:10 PM
> Subject: Re: 1988 Rebuilt Engine Stumbling at various RPM levels
> 2100-2300,
> 3400- 4000rpms
>
>
>> I had the mechanic set the timing according to Chris AKA
>> TentCentLife's (Samba user) process.
>>
>> What do I look for the AFM?
>> How do I take the proper reading?
>> What should the numbers be?
>>
>> Is there anything else I should be looking for?
>>
>> R
>>
>>
>> On Aug 8, 2009, at 4:39 PM, Scott Daniel - Turbovans wrote:
>>
>>> air flow meter is a good candidate.
>>> timing should at least be in the ball park of correct. Too advanced
>>> initially isn't good.
>>>
>>> but the old sensors back in !
>>> Scott
>>>
>>>
>>> ----- Original Message -----
>>> From: "Robert Stewart" <robertmstewart@MAC.COM>
>>> To: <vanagon@GERRY.VANAGON.COM>
>>> Sent: Saturday, August 08, 2009 11:39 AM
>>> Subject: 1988 Rebuilt Engine Stumbling at various RPM levels
>>> 2100-2300,
>>> 3400- 4000rpms
>>>
>>>
>>>> I just got my Rebuilt Engine back in my automatic 88 wolfsburg.
>>>> It's
>>>> been Stumbling at various RPM levels between 2100-2300rpm & 3400-
>>>> 4000
>>>> rpm's.
>>>>
>>>> It has good power through the band but if you are not pushing the
>>>> accelerator down and staying steady at any of the RPM ranges stated
>>>> above it will stumble once in a while, not continuously.
>>>>
>>>> The engine only has 100 miles on it so far. Mostly country road
>>>> driving with very little highway driving.
>>>>
>>>> It has a brand new bosch O2 sensor, all other sensors on the van
>>>> are
>>>> new.
>>>>
>>>> New Fuel Lines, Injectors are 2 yrs old. New fuel in the tank, all
>>>> old
>>>> fuel in the tank was removed. All new fuel lines on the tank as
>>>> well.
>>>> New Oil filter and Fuel Filter. Air Cleaner just cleaned.
>>>>
>>>> Any ideas of what I should be looking for?
>>>>
>>>> Could it be the advance timing on the engine?
>>>> Maybe it was set incorrectly?
>>>>
>>>> AFM problem?
>>>>
>>>> Thanks,
>>>> Robert
>>>> NY
| 
