Date:         Fri, 27 Jul 2012 13:35:25 -0700
Reply-To:     neil n <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil n <musomuso@GMAIL.COM>
Subject:      Fuel Injector (or wiring) Question: Deceleration,
              Fuel Shutoff Mode
Content-Type: text/plain; charset=ISO-8859-1

Hi all.

This is for a stock 2.1 WBX, Digifant.

Took my Westy to a shop for the first time in years. Am still tracking
down a surging issue. Shop owner loaned me an AFM "Vanagon Syndrome"
harness. This made no difference. Upon return of that part, owner took
time to demo his Snap On Vantage (graphing meter) on my van. (Throttle
switch test showed a nice square wave btw). He also kindly gave me a
brief tutorial on the Vantage. FWIW, this Vantage (4.0) has a
"Vanagon" section in it.

To test ECU fuel cut off (deceleration mode), he connected the Vantage
to an injector wire, revved engine to 3K RPM, dropped the throttle.
Meter graphed brief no voltage to that fuel injector wire, then
voltage resumed. So that's good. ECU obviously stopped the FI pulse,
then started it back up at idle. But that was one injector.

In deceleration mode, is there one controller (my term) in ECU that
turns off fuel to ALL injectors at the same time? Or, is there
separate controller for each injector?

On the 2.1, do all FI's pulse open at same time? (batch?) or in pairs?
e.g.  1, 4     3, 2

In other words, was this test of one injector sufficient?

I have to wonder if there's a fault in the wiring or ECU that allows a
fuel injector to pulse open in deceleration mode.

- residual fuel pressure is OK
- resistance of each FI tested via ECU plug OK
- throttle switch closes at idle
- full tune up was done
- O2/cat/muffler new
- engine grounds clean
- injector spray pattern same on each FI

Neil.

--
Neil n

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'88 Slate Blue Westy to be named.

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