Date: Sun, 14 Feb 2016 21:07:26 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: 1988 Vanagon GL tintop
In-Reply-To: <CA+az7_6pvojhw7hSp4ZGDeYw+VMdCrcUJigdmM=+t0Srmsff5Q@mail.gmail.com>
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Did you ask that shop to diagnose it for you or are you trying to do this yourself, even after the harness and ECU replacement? There are lots of connections including to the idle stabilizer. Don’t assume that if the valve is buzzing that it is good. I have seen them get bad coils so that they would open too fast and the controller can’t "modulate" them and I have also seen the insides get messed up with excess crankcase fumes or cleaning solvents. I have seen where both the valve and control unit needed to be replaced to get it all to work properly. There can also be another problem outside of the idle control system.
When troubleshooting by the part elimination process you want to make only one change at a time. In this cae yo also want to work in some sequence.
Without the idle stabilizer get it to run and idle 700-900 rpm.
Connect the O2 sensor and test it for proper operation.
Then connect the idle stabilizer. Restart engine after each change. See what you have.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of John Rodgers
Sent: Saturday, February 13, 2016 1:33 AM
To: vanagon@GERRY.VANAGON.COM
Subject: 1988 Vanagon GL tintop
Today the new (to me) ECU with Shoebox Monitor pigtail, arrived. Took,it to the shop and the mechanic there installed it. The new 7.5 fuse was in place and the new 2003 TDI starter turned the engine easily. With the replacement ECU in place, the engine fired right up. However, there were two immediate problems.
The engine hunted up and down rapidly over a significat range of rpm. As the engine warmed this tended to disappear.
The other problem was that the engine idled way to high, about 1800 rpm.
Shut it down, pulled the O2 connector, and the ISV connector, and started again. Engine idled nicely at 850 rpm!
What to do with this situation I don't know at this point. The ISV was working just fine, Could hear it buzzing beautifully. Left the isv unplugged but hooked up the O2 connection and 5he rpm jumped to 1400 rpm.
Don't know what to make of it.
Reseated the front wheel bearings and retorqued the spindle lock nuts and peened them down. Greased the C/V'S.
MONDAY I pick up my magic carpet!!!
Comments and opinions appreciated.
John
