Date:         Wed, 26 Aug 2009 11:44:27 -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 & Other questions
In-Reply-To:  <BAY132-DS701334B8E3B30058AAD5CA0010@phx.gbl>
Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes

Okay, I believe I fixed the stumbling....

Upon inspecting the engine bay I found that the mechanic forgot to
tighten down the hose clamp around the afm boot on the left side of
the afm connecting to the throttle body. I also place hose clamps over
the intake hose to the air filter from the main air feed coming from
the outside of the van.

I checked the afm with the multimeter and it checked out to be within
the spec of the bently. I also checked the throttle body connector
connector and it was in spec as well. I still need to check idle
stabilizer.

I stopped it stumbling while running above 2000 rpms but it does idle
a little rough, once in a while it seems a off when idling.

I am now trying to trouble shoot my cruise control system which does
not seem to be working. On the cruise control pump on the rear right
of the engine bay there is a small hose that goes from the bottom left
side to the right side and connects to a small connector just off the
main air line running off the pump, is this correct? it does not show
anything like this in the bently. I am going to take take a look at
the front of the van and try and check all the connectors around the
steering column and the computer. Now what I don't understand is that
I see some kind of computer device behind the glove box is that it?

Also is there a way to check and see if my front fan is working? Ever
since I put the external oil and tranny coolers on it, it never goes
on anymore. It was 95 degrees here the other day upstate and the temp
meter went just past the light on the gauge but once I was on the
highway and got out of the stop and go traffic it dropped back to the
where the light is on the gauge. Seems that the coolers are really
doing there job to keep the engine cool. I replaced all the sensors
when I did the engine rebuild. I turned on the ac system just to test
it and it does not work, just the fan does, but I noticed when I did
this the front radiator fan went on!?

One other thing, when wiring up rear back up lights do I need a relay
of some kind installed or can I just go direct? If so what size and
how does it get connected. Some people on the samba suggested yes and
some said no. Others said just connect the lights in series off one
side of the tail lights and not individually. Now I am totally confused.

Thanks,
Robert
NY



On Aug 17, 2009, at 6:36 AM, Dennis Haynes wrote:

> Robert,
> Stumbling is usually the result of ignition miss or fuel delivery. Not
> necessarily the actual mixture but a problem with maintaining fuel
> pressure
> or clogged injectors.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of
> Robert Stewart
> Sent: Saturday, August 08, 2009 2:40 PM
> To: vanagon@GERRY.VANAGON.COM
> 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
>