Date: Mon, 17 Apr 2006 08:41:30 -0500
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: 2.1 Engine idles at 2600 rpm; 2nd computer doesn't fix
In-Reply-To: <444383AB.8010409@comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Ken, interresting commentary about the ECU cooling.
I wonder if a computer cooling fan could be mounted some way to help
relieve this problem.
Just thinking out loud.
John Rodgers
88 GL Driver
Ken Wilford 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
>>>
>>>
>>
>>
>>
>
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