Date: Fri, 1 Nov 2002 12:19:57 -0600
Reply-To: John Rodgers <j_rodgers@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <j_rodgers@CHARTER.NET>
Subject: Re: high idle speed
Content-Type: text/plain; charset=us-ascii; format=flowed
Pat, you need to first check the operation of the idle stabilizer
valve(ISV) and idle stabilizer control. Together they control idle
speed on cold start, kick up the idle speed with AC running so engine
won't stall under the load when the engine is idling, and kicks up
engine speed when turning so the power steering pump load doesn't
stall the engine.
With the engine warm, the ECU basically takes the ISV out ot the loop
unless a load is placed on the engine by one of the accessories.
So you want to check its operation.
Warm your engine thoroughly - drive it down the road and back, then
turn off the engine. Disconnect the connector on the end of the Idle
Stabilizer Valve (ISV) Restart the engine. The idle speed should be the
same whether the ISV is connected or disconnected, provided the engine
is warm. With the ISV disconnected, if the idle is normal - 850-900 rpm
- then you most likely have a problem with the isv, idle stabilizer
control (black box behind the right rear stop light assembly) or
possibly a vacuum leak somewhere.
If, with the engine warm and ISV disconnected the idle speed is high, or
low, try adjusting it back to 850-900 rpm by turning the large flat
screw on the AFM. This is right up on top of the engine and easy to see.
Stop the engine, reconnect the ISV, let the engine cool completely. Then
restart the engine. The ISV should raise the rpm to 1000-1100 until the
temperature comes up, then the rpm should drop to 850-900. If with the
engine warm, the idle is not the 850-900 that you set, then look for a
vacuum leak .... a hose loose, a hole in a hose. something. If nothing
found, then you need to put a meter on the system. For info on that I
defer to the List Membership. There are those among us who are far more
qualified than I to discuss that operation.
Good luck.
John Rodgers
88 GL Driver
Pat Callaghan wrote:
> Hi all,
>
> On my 87 Westy, the idle speed seems to be too high. This has started since it has gotten colder here in Portland. The idle speed is anywhere from 1200-2000 RPM most of the time. The temp gauge only goes to the top of the white section. Seems too cold to me but the heat output is fine. When the weather was warmer, the engine usually ran at about 900 RPM. Is this normal or do I have a problem?
>
> I also wanted opinions on the compression. I checked it & it was 140, 140, 140, 135. Seems to be the bottom of the scale. Van runs pretty good with no apparent oil burning. Thanks.
>
> Pat Callaghan
> 87 Westy GL
> Portland, OR.
> www.patcal.com
>
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