Date: Wed, 10 Sep 2003 08:04:20 -0400
Reply-To: fty@CISCO.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: fty@CISCO.COM
Subject: Re: Idle valve and ISCU
I believe the humming you get when you initially turn the key is
the fuel pump running. The FP will pressurize the lines then shut
down unless it's told by the computer that the engine is running.
This is a safety "feature" to prevent fires. It's very hard to hear
idle valve hum from the driver seat ..
Check to make sure that the spring is pulling the throttle back
completely closed and that the idle switch "clicks" when it's all
the way back. You should also follow the Bentley procedure for
setting the basic idle.
cheers - Frank
In reference to the message from: Germain <reglys@SYMPATICO.CA>
>Hi all
>
>After opening my ISCU and changing the transistor and the 56 ohms =
>resistor, the idle valve is humming. I have noticed that after turning =
>the ignition key without starting the motor, the idle valve is humming =
>for maybe 15 seconds and after it stops. If I turn off the key and try =
>it again, the idle valve do not hum. Hum! Hum! (unless i try to start it =
>the day after).
>
>Anyway I tried to start the motor and the motor started right on . I =
>didn't have to play with the gas throttle. RPM was 1100. It was used to =
>be 700 RPM with a lot of stalling before. While the motor was warming =
>up, it started to surge going from 2400 RPM to 1400 RPM. I stopped it =
>and restart it. Everything seem to be OK. I did a small ride with it and =
>once again, it started to surge again. The motor was idling around =
>1500RPM and while I was braking, the RPM was going up and down. WOw when =
>it is acting like this, you have to push hard on the brake while waiting =
>on a traffic light.
>
>MY Question is: What could cause the surging? It is coming definitely =
>from the idle valve or the ISCU. I was running for months without the =
>ISCU working ( but I had rough warming up). Is the Idle valve usually =
>closed when the gas throttle is pushed? and reopened when the gas =
>throttle is released?
>
>Germain
>
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Frank Terhaar-Yonkers W4FTY TRA 8325/L3
Cisco Systems, Inc.
NSITE - Pineview Building - RTP
7025 Kit Creek Road PO Box 14987
Research Triangle Park, North Carolina 27709
fty@cisco.com voice(919)392-2101 fx(919)392-7339