Date: Mon, 28 Sep 2009 17:39:49 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: No injector spray pattern
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reply-type=original
a very useful test I find to do with the distributor, or 'a distributor' if
you have one laying around....
and you really should have a known-good spare to keep handy for emergencies
and troubleshooting times like this is ..........
remove the distributor from the engine ( or just unplug the one that's in
the engine, and plug that connector into your spare distributor ) .....
in other words, rig a distributor so it's plugged in and you can turn it
with your fingers.
Remove the center plug wire from the distributor cap and arrange it near
ground on the engine so you can watch the spark from the coil zapping to
ground.
turn on the key,
turn the distributor with your fingers.
watch for two things .......
one, the big spark jumping to ground from the coil
and two.....listen for the fuel pump to be triggered and run.
Each time there are a few pulses from the distributor, the ecu should run
the fuel pump a few seconds.
If it does not, something is wrong.
with this method you can also tilt and rock the distributor while you are
testing, to check for poor contact where the wires join the distributor, or
just inside the distributor. You might discover that it works held at one
angle, but not the other.
here's another test you could try if you want to work from the injector end.
Hang 2 injectors out where you can see them spray.
remove the wires from one.
leave the key off. Hot wire the fuel pump or fuel pump relay so the fuel
pump is running continuously.
jury rig 12 volts with a small jumper wire to one side of an injector, to
the tiny terminal there after you remove the plug.
ground the other side with a small jumper wire.
the injector sure should click, and sure should spray.
if it does that, you know that each tested injector CAN spray, if it gets
the 3 things it needs, power on one side, ground on the other, and fuel
under pressure to it.
The power supply side of the injector 'should' not be that hard to trace
through.
you have the Bentley manual ?
you gotta have one.
Depending on what year vanagon you have, I might have one for sale.
Basically...........if the ecu is powered up, the fuel injectors are getting
power, all grounds are good, there is fuel pressure to the injectors, and
the distributor is doing what it should do .....it should fire the
injectors.
I think this is a 2.1.
But in case it's a 1.9 , I had this happen once. I swapped in another
Igniter and the van would not start. Took me a while, but I finally found
one white wire, that goes from the igniter to the ecu .......had pulled out,
or been pushed back from the igniter plug and wasn't making contact. This
one wire is the only wire that connects the fuel injection system and the
ignition system on a 1.9. Essentially, the ECU did not know the engine was
turning over without that one signal, or wire connection, and thus wouldn't
fire the injectors.
if 2.1 ........I see on page 97.105 for 1987 vanagon a green wire that goes
from terminal 1 of the coil to pin 25 of the ecu.
Pin 1 of the coil is where 'tach signal' would come from ,
and where the tach is wired to if it has one I'd think.
It appears to me that if the signal from pin 1 of the coil on the green wire
does not get to pin 25 of the ecu, the ecu might not know the engine is
turning over ands thus won't fire the injectors.
I'm not saying that is 'the whole story' on how ignition and ECU are
intertwined to fire the injectors, but it is something you can check.
Just don't do anything funny at the ecu with the key on !
never even disconnect the ecu unless the key is off of course. Measuring
continuity of wires to to the ecu with ecu removed and key off is ok,
Starting on page 28.39 are some 2.1 Digifant Ignition tests .
you gotta have a Bentley manual really.
Ok........hoping for a breakthrough here on this problem for you soon !
Scott
www.turbovans.com
----- Original Message -----
From: "TJ Hemrick" <x53gunner@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, September 28, 2009 9:58 AM
Subject: No injector spray pattern
> Rocket,
> I realize it was discussed previously, in fact, it was less than a week
> ago. Previously, it was unknown why the van was not running as it had
> fuel,
> spark, air. Turns out, fuel stopped at the injectors. I should have
> figured that out sooner but I was pretty frustrated and started playing
> "swap-tronics" instead of troubleshooting. Now that we cracked that nut,
> I
> pulled both banks of injectors and I do NOT have a spray pattern. They're
> BONE dry. THAT is the problem. I should have started at the Injectors
> and
> worked backwards from there but I assumed (incorrectly) it was the
> pump/filter. Well, we all know what happens when we "assume" so I bear
> the
> responsibility on that one. I already payed the price in extra work so my
> dues are done. As per Ken Wilford, I'm going to swap the distributor and
> see if the hall sensor is the issue since it's the trigger for the ECU.
> Not
> much else to check as I've been through every ground and connection in the
> back end of that van, all the fuses, relays, and anything else I could
> unhook, clean, and reconnect. On top of that, I've already replaced the
> fuel pump, ECU, and filter as a double check. Why, at this point, the
> injectors are dry is the issue.
>
> TJ
>
> Date: Mon, 28 Sep 2009 06:40:16 -0700
> From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
> Subject: Re: Fuel injection trouble
> What Mike S said. The pulses that drive the injectors are too brief for
> your basic meter to capture and display. You'd need a fancier "peak hold"
> meter or oscilloscope to properly measure them.
> What you're seeing suggests that the injectors are being driven, confirm
> by checking for spray, as Mike S suggests. The subject was discussed here
> less than a week ago, and some procedural and safety tips were mentioned.
> --
> Mike "Rocket J Squirrel" Elliott
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
> Bend, OR
> KG6RCR
>
>
> Date: Mon, 28 Sep 2009 09:11:43 -0400
> From: Mike S <mikes@FLATSURFACE.COM>
> Subject: Re: Fuel injection trouble
> At 08:24 AM 9/28/2009, 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.
> If you're just using a simple multimeter to measure the voltage, that
> sounds correct. The injectors are pulsed, so even if they get full
> voltage when pulsed on, the meter will average the voltage down. You
> would need an oscilloscope to see the actual drive voltage.
> Pull the injectors on one side, and check the spray pattern.
> ------------------------------
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