Date: Fri, 10 Oct 2008 13:28:15 -0700
Reply-To: "B.J.R." <beer_eighty@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "B.J.R." <beer_eighty@YAHOO.COM>
Subject: Re: Technical question re: Injector firing signal
Content-Type: text/plain; charset=us-ascii
---DIGITAL VOM METER ATTACHED TO PIN #1 FROM THE BACK SIDE WITH ECU CONNECTOR COVER REMOVED AT ECU SHOWS A MOMENTARY (2-3SECS) 5V AT "KEY ON" THEN RAISES TO 12V, STAYS LIT.
TURNING ENGINE OVER, VOLTAGE FLUCTUATION, ---WITH LED TEST LIGHT, BRIGHT FLICKER
SO I AM GETTING A SIGNAL TO THE ECU,
READING THE DIGITAL VOM DURING CRANKING, VOTAGE WOULD DROP TO 5V THEN JUMP TO NINE THEN DROP TO 5 ETC.
I ASSUME THIS IS THE LIMITATION OF MY CHEAP VOM, NOT THE ACTUAL FLUCTION READING. THE DISPLAY SHOWS A DROP AS THE NUMBERS GO DOWN BUT NOT LIKE AN ANALOG WOULD. AND THE MOMENTARY SIGNAL SHOWS THE RISE IN VOLTAGE BUT DOESNT REGISTER FULLY BECAUSE THE SIGNAL IS "OFF"
BUT I HAVE IN HAND AN EXACT REPLACEMENT FOR THE ECU, PLUG IT IN,
SAME CONDITION, NO SIGNAL AT THE INJECTORS
HOW DOES A SINGLE WIRE SIGNAL DETERMINE WHICH INJECTOR WILL FIRE?? IE: 1,2 3, OR4?
IS THERE ANOTHER SIGNALING COMPONENT?
AND
ARE THERE ANY METHODS TO TEST THE COIL? BESIDES A $60 REPLACEMENT?
IT PASSED ALL THE RESISTANCE AND CONTINUITY TESTS
IT MAKES A BRIGHT WHITE SPARK
I AM OFFICIALLY OUT OF IDEAS
If you attach the red lead of a digital VOM to ECU pin #1 and the
black lead to ground and set the VOM to AC voltage then have someone
crank the engine you can see if you get some AC voltage on the meter.
If you see some strong voltage then the ECU is getting the signal.
Try to test it from outside first. if there is no voltage suggesting
the presence of a signal then there is no point to check it from inside.
You can check the injectors this way too. Just attach the leads of the
VOM meter to the leads of the injector. The polarity of the leads does
not matter because you are check AC signal. When the engine is cranked
the meter will tell if you are getting a signal. You can use an alalog
meter if you do not have a digital one. Just make sure to set it to
AC volt and start with 20 - 30 volt range. The signal at the ECU pin #1
and the injector signal should be fairly strong to observe this way.
If you have a spare coil you may want to try it. A bad coil may still
produce some sparks but sends noise to the ECU which will be filtered
out by the ECU leaving no signal to drive the ECU.
Good luck. Hope the problem is fixed by tomorrow.
David
--- On Thu, 10/9/08, B.J.R. <beer_eighty@YAHOO.COM> wrote:
> From: B.J.R. <beer_eighty@YAHOO.COM>
> Subject: Re: Technical question re: Injector firing signal
> To: vanagon@GERRY.VANAGON.COM
> Date: Thursday, October 9, 2008, 8:50 PM
> I would open the case of the ECU and check pin #1 from
> inside
> provided that you have done checking from outside. If you
> have
> a digital VOM you can measure AC voltage on pin #1 from
> inside.
> Start from a higher range then switch to lower range until
> you
> get a reading. You should see a few volts up to 10 or 15
> volt.
> If it is zero that apparently means trouble there.
> ----IM GONNA GO TRY THAT NOW. SOMETIMES WHEN ONE HAS BEEN
> STUCK ON A PROBLEM FOR A WHILE,
> THE OBVIOUS IS OBSCURED
> If you have a scope it will be the best tool to see the
> signal.
> --A SCOPE???
>
> Check all your ground strips. It could be a grounding
> issue.
> ---REGROUNDED ALL GROUNDS, REAR COMPARTMENT, ENGINE BLOCK,
> TRANNY, BATTERY,
> If you can find an ECU to try it will tell if it is the
> culprit.
> ---IN THAT PROCESS, BUT ILL CHECK ECU #1 FROM INSIDE -OR-
> THE BACK OF THE ECU CLIP FIRST
> Or you can take your ECU to try it on another van.
> HARD TO FIND AN 82 ROUND HERE.
> David
>
>
>
> --- On Thu, 10/9/08, B.J.R. <beer_eighty@YAHOO.COM>
> wrote:
>
> > From: B.J.R. <beer_eighty@YAHOO.COM>
> > Subject: Re: Technical question re: Injector firing
> signal
> > To: vanagon@GERRY.VANAGON.COM
> > Date: Thursday, October 9, 2008, 6:09 PM
> > Here IS A diagram of the system
> >
> >
> http://s417.photobucket.com/albums/pp260/volksproblem/?action=view¤t=PA040039.jp
> >
> >
> > I have tested continuity in ecu wires pin #
> > 1, 13, 15, 14, 32, 29, 33, 10,5, 16, 17, 20, 4,
> > Ox sensor
> > 4, 8, 6, 7,
> > ignition control
> > 2, 5, 6, 3, 1, 4
> >
> > All are acceptable range.
> > gave all wires motion to check for loose or weak
> > connections.
> >
> >
> > HOW DO I CHECK FOR SIGNAL FROM IG COIL TO ECU #1 ???
> >
> >
> >
> >
> > ----- Original Message ----
> > From: Scott Daniel - Turbovans
> > <scottdaniel@turbovans.com>
> > To: B.J.R. <beer_eighty@YAHOO.COM>;
> > vanagon@GERRY.VANAGON.COM
> > Sent: Thursday, October 9, 2008 5:57:33 PM
> > Subject: Re: Re: Technical question re: Injector
> > firing signal
> >
> > do you know how to check continuity with a volt-ohm
> meter ?
> > essential to checking wiring harness continuity.
> > the less expensive ones, analogue, start at under 5
> > dollars- made in china
> > of course.
> > Digital volt-ohm meters, which are far more
> > capable.......like for checking
> > oxygen sensor output .......
> > cost more of course. Recently my 20 year old one died
> -
> > Radio Shack's best
> > one was 70 bucks I think.
> > Scott
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