Date: Mon, 28 Sep 2009 10:11:12 -0400
Reply-To: Ken Wilford <kenwilfy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ken Wilford <kenwilfy@COMCAST.NET>
Subject: Re: Fuel injection trouble
In-Reply-To: <989ea5a20909280524x18fc82d4y2057468881e0c5b7@mail.gmail.com>
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According to the diagram on page 97.106 of the Bentley you should be
seeing 12 volts from the ECU relay to the injectors and the ECU is
pulsing the grounds. That is how the injectors fire. In your case I
would check the ECU grounds to be sure they are good since the injectors
are being grounded through the ECU and since you have swapped in known
good ECUs and it isn't helping then maybe the problem is that either
there is a bad wire in the harness somewhere (check the diagram and test
it wire by wire if it comes to that) or that there is a bad ground (more
plausible in my experience). There are two grounds to check. One is on
the driver's side head and connects to the firewall with a grounding
strap. The other is under the rear seat by the ECU. The second may
look like it is hooked up and good but some times the lug that it is
hooked to is rusting out from the back side so try grounding it
elsewhere like to where the seat belt attaches, just temporarily and see
if this fixes the problem.
The other likely culprit would be the hall sensor in the distributor. I
can't remember if you have already tried to replace the distributor with
a known good one but that would also be a good idea since the pulse is
regulated by the hall sensor. You can try to test it but in my
experience the best way is to swap in a known good distributor if you
can get your hands on one because the Bentley test is just not conclusive.
Hope this helps. Let me know if you need any more help or any parts.
Ken Wilford
John 3:16
www.vanagain.com
TJ Hemrick wrote:
> I'm not getting any fuel out of the injectors but definitely have good
> clean fuel in the lines. I had some help and found the injectors were
> getting voltage but it's incredibly low. It peaks at 4 volts and within two
> revolutions, it holds at 2-3 volts max. I have NO idea what could cause
> that or what to check next. I checked the relays and they are getting
> proper power where they should and have ground where they should. I checked
> all the wire grounds, as many connections as I could find, swapped out the
> two relays in the engine compartment, and swapped another ECU just for
> giggles (no change). I've never had any problem like this (low voltage).
> It's either been a bad wire (no voltage/short) or bad a component. Anyone
> have something similar or ideas on what or where to look next?
>
> TJ
>
> 87 GL
>
>
