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Subject:Re: Pulsing idle UPDATE
From:Joshua Van Tol
Date:Wed, 14 Apr 1999 18:04:29 -0500

>- Replace the idle stabilizer (balck little elecrical box located
>behind the right tail light) with one from the junk yard.
This is only for '86 and newer vans, which use a completely different
mechanism to regulate the idle speed. You do have an idle stabilizer, but
it works completely differently, and is located in front of, and below the
coil.

>- Disconnect the idle throttle switch or lower idle RPM
This only masks the problem. The real problem is that the idle is too high,
probably because of a broken aux air regulator, throttle valve, or an
intake leak.

>- Replace O2 sensor:  BOS 11027     OXYGEN SENSOR  single wire
Check the sensor before you replace it. All you need is a volt meter. Email
if you need instructions.

>- check the coolant sensor
>- check the air flow meter
If you aren't getting horrendous fuel milage, nix the above two
suggestions. If the mixture were rich enough to cause high idle, it'd cause
low fuel milage, and probably fouled plugs.

>Now the pulsing is gone, but my idle is way to high. I don't have a
>tach but my guess is in the 1500 - 1700 range. Now there is no change
>in idle speed between warmup and warm engine. Judging from that, is
>my coolant temp sensor the problem?
>I guess if the ECU doesn't get proper temp readings, it causes the
>engine to run rich to compensate for supposedly cold outside
>temperatures.

I'll bet your auxillary air regulator is stuck open, or your throttle plate
is sticky. I have both of these problems on my '85. I managed to improve
the situation by adjusting and cleaning the throttle valve, but it, and the
aux air regulator are just worn out, and need to be replaced.

Joshua Van Tol -- jjvantol@uswest.net