How about a vacuum leak?

Thanks,
Ken Wilford
John 3:16
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-----Original Message-----
From: greentabe-vanagon@yahoo.com [mailto:greentabe-vanagon@yahoo.com]
Sent: Monday, April 17, 2006 4:21 PM
To: Ken Wilford
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: 2.1 Engine idles at 2600 rpm; 2nd computer doesn't fix

Ken,

Thanks for the idea.  Tried a new ECU; no change.  Still idles high.

tabe

--- Ken Wilford <kenwilfy@comcast.net> wrote:

> I had a customers van here not too long ago with idling issues.  Of
> course you need to check your grounds and the throttle position switch
> first to see if these could be bad or out of adjustment.  If they are
> fine then I usually swap over the idle computer from a good running
> van.  If that doesn't work I swap over the valve on top of the engine.
> Still bad?  I was scratching my head on this one, then I just tried
> swapping over the engine ECU.  Idle went back to normal.  Apparently
> something in the Engine Control Unit itself (under the back seat) was
> causing the idle problem.  Just an idea.  I have all of these parts to
> swap around so it makes it easier for me to test for these problems.
> You could try swapping in an ECU from a good running van from 86-91
> (they will all work) and see what happens.  I have rebuilt units with a
> one year warranty for $250 if you find you need one.
>
> Just FYI:  The factory 2.1l ECUs had problems with three things.  They
> decided to integrate the ignition module into the ECU so it got hotter
> than the older ones with the separate ICM.  Then they stuck it under the
> rear seat where it gets no air flow.  Then who ever was building the
> boards decided to do a crappy solder job on several of the connections
> (cold solder joints).  Murphy's law was in full effect that day!
>
> Hope this helps,
> Ken Wilford
> John 3:16
> www.vanagain.com
>
> Tabe Johnson wrote:
>
> >To recap:  Both my engine and that of Larry Himli (both 2.1s) idle
> >around 2400-3000 rpm.  In my case, it used to be that it would just
> >do that till it got warm, then it would idle properly, and sometimes
> >pop up to idle at 2400-3000 rpm.  Now it does it all the time.  I
> >swapped out the idle computer.  No change. My temporary  fix: Unplug
> >the idle air bypass solenoid.  Engine runs great otherwise.
> >
> >
> >Larry's AC thing is interesting -- it says that the idle computer is
> >at least trying...  I'm still wondering about the computer.  There
> >was a post a few years back about fixing damaged computers by
> >replacing a one transistor that always blew.
> >
> >The inputs and outputs are pretty simple.  I went through this too,
> >and heres what I came up with:
> >
> >IDLE COMPUTER INPUTS:
> >Idle Switch
> >PS Switch
> >AC Switch
> >Hall Generator
> >Temp sensor 2
> >Power from relay
> >
> >IDLE COMPUTER OUTPUTS:
> >Idle air bypass
> >
> >Ideas?  Anyone?  Beuller?
> >
> >
> >
> >tabe johnson / 87 westy
> >
> >--- Larry Himli <lhimli@msn.com> wrote:
> >
> >
> >
> >>Bummer, I was so sure the relay would fix it....but no luck.  It
> >>still revs up to about 2K and at least it oscillates back and forth.
> >>I turned on the air conditioning and it really revved up.  So now we
> >>have to try something else.  Have you studied the wiring diagram?  I
> >>will try to look it over and see what might feed the relay, etc.  At
> >>least it isn't raining
> >>
> >>
> >
> >
> >
>