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

[jtrealty@xxxx]

Even with the air sensor plate at rest position some fuel must flow. 
How would you expect the engine to idle without fuel? It is very 
difficult to accuratly diagnose the fuel system without an injector 
tester and a fuel pressure gauge. The best advice is to clean 
everything up as good as you can, fix all leaks, see that all of the 
injectors have a decent pattern and flow equally. Change the fuel 
filter and then see how well the motor runs. Make sure you have 
flushed all of the kerosene out of the system before trying to start 
the motor. This is a continuous injector system ie: it always flows 
fuel to all injecters, it doesn't know when each cylinder fires. Be 
very careful that you have NO fuel leaks under pressure, it can become 
very dangerous if in fact there is even a minor one.
David Teitelbaum
vin 10757



-- 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