Re: DMC How are the fuel injector suppose to work in this system?

[srubano@xxxx]

If the engine is off and you are just running the fuel pump you 
should get NO fuel from the injectors. When you press down on the 
airflow sensor you should see a stream of fuel spray out. If your CO 
is off or the air flow meter is binding (slightly down, stuck open a 
little) this would explain why you are getting fuel from the 
injectors when the engine is Off and the fuel pump is running and 
the air flow meter is not pressed down. Check that the plate on the 
airflow meter is centered (page D:01:16, 3rd bullet under "Mixture 
Control Unit"). Make sure it has the required clearence from the air 
meter housing opening otherwise it will not close fully.

Steve

--- In dmcnews@xxxx, jugeauj@xxxx wrote:
> 
> Hi All,
> 
> Not having played with this type of injection system before I'm 
not sure
> of what I'm looking at concerning how the fuel injectors are 
supposed to
> work.
> 
> I've finally gotten around to hooking the fuel lines back up on 
#4337.
> Long story short, from what I can deduce and from what I've been 
told from
> previous owners (#2 and #3, I'm #4), the car sat around with water
> throughout its fuel lines for the better part of ten years.
> Suffice it to say a lot of parts have been replaced.
> 
> Using kerosene (less explosive fumes to contend with), I 
unhooked the
> fuel pump and wired a 12V battery across it (happen to be more 
convenient
> at the time than bypassing via the fuse box, etc.) and watched for 
what
> kind of crud came through.
> 
> Then came the check for leaks around the distributor, etc.
> Mostly out of curiosity, I pulled two injectors out and ran the 
pump again.
> Both injectors emitted a thin stream (not a spray) of fluid.
> Just to test the injectors themselves I went ahead and pressed 
down on the
> airflow sensor and got a nice spray pattern (yeah, I know the 
catalytic is
> probably going to love me for that).
> I was lead to believe that with the airflow sensor completely 
closed (as in
> the case with the engine not running) no fuel should make it's way 
to the
> injectors. Is this true?
> Is the distributor supposed to allow raw fuel into the intake or 
is there a
> problem stemming from either of the following:
> 1) Central fuel plunger valve (sorry, don't know the correct name 
for it)
> in the fuel distributor is bad?
> 2) The 12V battery I used couldn't work the pump up to around 
65psi thereby
> not charging the system with enough fuel pressure for the plunger 
and other
> associated components to function properly?
> 3) Fuel filter was significantly plugged up to restrict fuel flow 
thereby
> yielding the same problem(s) as in #2)?
> 
> I apologize if this turns out to be a relatively basic question.
> I only get to work on the car on weekends and didn't give myself 
enough
> time to experiment on my own (getting fuel pressure readings, etc).
> I figured I'd ask the group during the week to fuel myself with 
more
> information to work with this coming weekend.
> 
> Thanks a lot,
> 
> Louis