Date: Wed, 8 Oct 2008 11:02:20 -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
This didnt seem to post directly from vanagon.com so I'll do it from my mail...
First, I will track down a noid light. Never heard of one untill this morning.
I had tested my AFM previously, I will recheck again to my abilities.
I'm just checking for resistance values, yes?
I replaced the temp sensor II about three weeks ago.
"The ECU has to see the that the engine turning - it gets that from the
distributor/ignition system.
throttle position switch"
I'll have to look into this, unsure how to test but I am getting spark to
all cylinders and my hall sensor generator tested ok per Bentley.
Does ECU see ignition is turning or AFM is taking in air???
Where is the signal sent to the ECU from distributer???
I dont believe I have a TPS on my aircooled.
But I did re-track my AFM about the same time I replaced the temp sensor.
( i lightly bent the control arm to an untouched part of the signal track)
" and the ECU triggers the fuel pump relay."
(?? doesnt the AFM trigger this??)
"Does the fuel pump run for a few seconds when you turn the key to 'on' ?"
I have fuel pressure (36psi) but not at key on
At "key ON" ONLY the injectors, terminal #10, & AFM #39 (which eventually
powers the fuel pump) have energy.
Fuel does not pump untill turn over, energized from the second relay, then
AFM#39 takes over ONLY when there is air being drawn in the intake (safety
shutoff, or fuel would pump in an accident, right?)
I fell a bit confused now,
Some clarification please
----- Original Message ----
From: Scott Daniel - Turbovans <scottdaniel@turbovans.com>
To: B.J.R. <beer_eighty@YAHOO.COM>; vanagon@GERRY.VANAGON.COM
Sent: Tuesday, October 7, 2008 8:20:18 PM
Subject: Re: Technical question re: Injector firing signal
the answer to your last question ...............yes, there sure are.
first............the ONLY way I ever check for an injector signal at an
injector plug is to plug a Noid Light into the wire connector, then crank
the engine.
If it flashes............the ecu is firing the injectors.
Cranking it on a remote starter switch is much better since you are right
there by the engine.
90 % of the time on a no-start........I find that the ecu is triggering the
injectors, and that's not it.
about inputs to the ECU...........which it depends on to know how long to
hold the injectors open are........
engine temp,
and I think there's a temp sensor in the air flow meter - see Bentley
manual.
The ECU has to see the that the engine turning - it gets that from the
distributor/ignition system.
throttle position switch
Of course lack of inputs or correct inputs can lead to a no start condition.
you also need fuel in the lines under pressure..........as controlled by the
fuel pump relay and fuel pump, and the ECU triggers the fuel pump relay.
Does the fuel pump run for a few seconds when you turn the key to 'on' ?
the 3 fast things to check for a no start are :
injector pulse,
ignition,
fuel pressure.
You also need to know the spark plugs are not worn or wet-fouled. If
they're old and worn .........you can get a floods-but-won't start condition
fairly easily.
Scott
www.turbovans.com
----- Original Message -----
From: "B.J.R." <beer_eighty@YAHOO.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, October 07, 2008 7:51 PM
Subject: Technical question re: Injector firing signal
>I have an 82 aircooled CA Westy,
>
> My van used to run fine, a stumbling at light load turned into it not
> starting any more.
>
> This is the only malfunction I can find in the system is...
>
> I have =battery voltage(12v) at the + injector connector(to ground) on the
> wiring harness, key on,
> but no signal (using LED voltage tester) when turning engine
> over(connector + to connector ground at ECU using test light).
>
> I have continuity on; each wire in the harness& all three grounds on the
> ECU.
> I have voltage to the ECU
>
> I'm assuming it's the ECU and am in the process of getting it replaced.
>
> THE QUESTION IS...
>
> Is there any other component, or combination of components that gives the
> ECU the signal when to fire the injector??? That may be the culprit for
> not getting a signal at the injector?
