Date: Fri, 16 Oct 2009 17:20:05 -0400
Reply-To: Jeff Michal <jeffmichal@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jeff Michal <jeffmichal@GMAIL.COM>
Subject: Re: Start Idle Issue
In-Reply-To: <C6FE46FC.9C63%dave.arthur@nscc.ca>
Content-Type: text/plain; charset="us-ascii"
Thanks for the tip. This sounds like exactly what I'm after.
-----Original Message-----
From: Dave Arthur [mailto:dave.arthur@nscc.ca]
Sent: Friday, October 16, 2009 2:51 PM
To: jeffmichal@GMAIL.COM; vanagon@GERRY.VANAGON.COM
Subject: Re: Start Idle Issue
Hi Jeff
From my limited experience, I would say that the open loop mixture setting
was incorrect. This setting is done on the AFM, a cap must be remove to
access a pot that controls the mixture. The AFM is part of the entire run
cycle of the engine. The initial setting is used until the engine, under the
direction of the o2 sensor goes closed loop.
I would guess that the mixture was set with the old injectors and requires a
rest with the new units.
I had a similar situation when I replaced an AFM, engine was fine closed
loop but rich when cold. The above adjustment cured the issue.
The next problem becomes how to make the adjustment. The CO must be measured
before the CAT, if you want to have an exact setting. An alternate method
would be to adjust it until it 'works right'
Best Regards
Dave
On 16/10/09 3:26 PM, "Jeff Michal" <jeffmichal@GMAIL.COM> wrote:
> Hi everyone. Could use some public review of a problem I'm having with my
> 90 GL Vanagon. It's got the stock 2.1 liter engine, ~130k on it.
>
>
>
> I am seeing an issue with the engine idle immediately after start. The
> engine seems to run rough for a short time, the amount of time seems
> dependent on the engine temperature. If the engine is warm, the rough
> running lasts for 1-2 minutes. If the engine is cold, the time is pretty
> much 1 or 2 minutes after the engine heats up to halfway to the LED on the
> temp gage. During this time, the engine is idling about 650-700 rpm. If
I
> give gas, the engine seems to flood and try to die.
>
>
>
> Recently I have had to replace the throttle linkage and all 4 fuel
> injectors. The problem came about after the fuel injectors were swapped
> out. From what I know about the efi, it has a short period (1-2 minutes)
> where it runs in an open loop prior to engaging the mass airflow sensor
and
> entering a closed loop with managed air and fuel volumes. It seems to me
> this open loop period is where the problem must be, but I'm not sure how
to
> resolve it.
>
>
>
> Any ideas are appreciated.
>
>
>
> Jeff Michal