Re: More on CIS Fuel problems/questions

[Ron Pieper <rapieper@yahoo.com>]

--- "S.Coleman" <deadbolt@mindspring.com> wrote:
>If I
> pull an injector and *don't* lift the air sensor
> plate....should fuel spray
> from the injector.  My understanding is NO. 

I believe that's correct...

> If it
> does,...then either the
> injector is bad...i.e.. not able to withstand
> pressure from the fuel
> distributor 

Well, injectors can go bad by leaking, then they'd
spray when not desired.

OR the fuel pump isn't able to "pump"
> fuel with enough pressure
> behind it

Don't get your logic here...how could low pressure
cause a leak?

.....OR the fuel pressure regulator isn't
> able to put enough
> "control" pressure on the control plunger allowing
> the plunger to rise
> releasing fuel into the fuel lines and out of the
> injectors.  

Seems logical, but I don't know if this is a common
failure mode.  THis seems the most likely so far. 
Have you ohmmetered the leads to the CPR?

I really doubt
> that all my injectors went bad at the same time? 
> (not that it couldn't
> happen?)  

I doubt it too.  Would have to be massive dirt.  Pull
the banjo fittings off the CPR and see if the screens
are full of crud. At least that'd be an indication of
serious dirt in the system.  

Do they leak after the FP is switched off?  (BTW, in a
pinch I have saved leaky injectors by running the tip
of an ice pick around the perimeter of the business
end, with pressure applied.  Must've dislodged some
dirt, and the injector was fine from then on.  Don't
do this unless you're ready to toss the injector.

Plus,...all the cold start injector
> diagnosis from the Bentley's
> and the FAQ from .org test fine.......but still I
> have no fuel coming from
> the cold start valve.  hmmm?  

Did you lay 12V directly across it?  Bypassing thermo
time switch, etc?

Something tells me
> that the fuel pump is
> dying...(does seem a bit more loud than either of
> the two on my 16v's)  

In my experience, audible = dead or dying, but that's
not 100% reliable (had one go bad, was as quiet as a
fart in church).  I'd check pressures (if you can)
before replacing.  Or swap it and keep your old one
for a spare.

But
> the bolts on the FPR are a bit worn like they have
> been taken off a time or
> two......which leads to the other guess......

Did you do the flow test?  (injectors spraying into a
graduated flask for xx seconds)?

Anyone
> tell me if my thinking
> is close or at least on the right track here. 

Your logic seems sound but you are trying to fix two
problems at once!  This could kill you!

>.but I
> could get more from it
> if I had a working fuel distributor.

DO we know for a fact that your distributor is bad
yet?

Man, you gotta get a fuel pressure gauge with a banjo
fitting and a double-length banjo bolt.  Invaluable
for diagnosing CIS.  Frankly, I'd work on the cold
start issue...if I recall your symptoms, it was a
starting problem??

Ron


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