Re: [DML] Re: impossibly high fuel pressure?

["Andrei Cular" <acular1@xxxx>]

I haven't had too much time lately to pay attention to this thread but it
sounds like something I just went through. First change the fuel filter.
Then remove and have the injectors cleaned or replace them, I got new ones
for $19 each from my local FLAPS.

My car sat for 8 years, more than enough time for the gas to turn. I
cleaned the entire fuel system and replaced most of it. But did not get
100% of the trash out of the system and ended up plugging up the injectors.
Each injector has a small screen/filter that you can not remove and if you
try to punch a hole in to allow the gas to flow you will destroy the
injector.

If you have the pressure regulator in pieces you tell if it is working by
hotwiring the fuel pump on then with a small screwdriver press the small
recess in the center of the diaphragm where the rod sits. As you press it
with one hand move the air flow sensor plate with the other. if the
regulator is working you will feel the resistance change on the sensor
plate.

If you have any questions email me off the list, I will get back to you
faster.


Andrei Cular



----- Original Message -----
From: <Soma576@xxxx>
To: <dmcnews@xxxxxxxxxxxxxxx>
Sent: Wednesday, April 11, 2001 12:49 AM
Subject: Re: [DML] Re: impossibly high fuel pressure?


> Hello David (and the rest of the list),
>
> you have so many things to say, i'll just answer each part individually or
> else we'll both get very confused!!
>
> n a message dated 4/10/01 9:21:40 PM Central Daylight Time,
> jtrealty@xxxx writes:
>
> << > Before you give up I have some ideas you can try. If indeed your
> > primary pressure is too high besides the primary pressure regulater
> > being stuck (which you say isn't) >>
>
> i have pulled the bolt and spring/pin assembly. the whole thing is very
> clean with no corrosion or debris. the pin in the spring moves easily,
and
> the hole in the bolt is not plugged from either direction. so i must
assume
> that this piece functions correctly. after all, there's hardly anything
to
> fail, except for the diaphragm inside the fuel distributer.
>
>
> <<another possability is a restriction
> > in the return line from the regulater to the tank.>>
>
> from the fuel distributer to the tank, everything is kosher. remember?
we
> put a bucket around the return line in the tank and we measured out the
> correct amount in one minute (2 liters) as stated in the shop manual. i
also
> removed the return line from the control pressure regulator which goes
into
> the side of the fuel distributer. i ran the fuel pump and fuel flowed out
> very freely, without sputter or dripping. this says that the control
> pressure regulator is not plugged on the return end, correct? i would
assume
> so.
>
> << Since your resting
> > pressure is about right the fuel accumulater is probably OK.>>
>
> i would be inclined to agree.
>
>
> <<A quick
> > and dirty test is to remove the return line from the regulater and rig
> > up something temporary into a pail and see if the pressure is now in a
> > more normal range. >>
>
> can you describe this in greater detail? i don't know if you are talking
> about the return on the control pressure or the primary pressure. and
when i
> remove it, from what end of the hose? if you could get more specific, i
> might be able to see what you mean, and maybe i've already done that.
>
> <<I think the noises from the pump are just it trying
> > too hard against the high pressure, after you can get the pressure
> > right the pump might be alright. >>
>
> that would make sense if the INTAKE side of the fuel system were plugged.
> however the fuel pump is capable of putting out over 120 PSI of fuel
pressure
> (typically they are twice as strong as the system requires), so i do not
> think the pump is strained. i was reading about 7.5 bar of pressure
which
> is around this PSI level. i believe the pump is as strong as it should be,
> but it might not be CONSISTENT!!
>
> <<If you cannot regulate the primary
> > pressure don't bother checking the control pressure, it will be too
> > high also, it also dumps into the return line to the tank and besides
> > it receives "regulated" presssure from the primary regulater so if
> > that is too high the control pressure reg can't reduce it enough. >>
>
> this is what i believed about two days ago. however i have since talked to
an
> engineer at bosch and a K-Jetronic guru at a local import dealer here, and
> they both say that it is possible to read pressures in excess of 6 or 7
bar
> due solely to a failed control pressure regulator. the primary pressure
> regulator may be working just fine, however it is possible to get too high
of
> pressure AFTER the primary pressure. i don't really understand it, but
both
> of these guys insisted that the control pressure regulator is at fault.
the
> guy at the import dealer noted that i said my system pressure was measured
at
> about 6.5 bar today and my control pressure is at 3.5 bar on a COLD
ENGINE!!!
> this is definitely not right he said, and the problem lies within the
warm-up
> regulator (CPR to us DMC guys). the problem is the difference between the
> system and control pressures is too narrow. the warm up pressure on a
cold
> engine is spec'd at around 1.5 bar (i don't see that spec in the shop
manual,
> but he insisted that all of these systems are the same, even on the
> DeLorean), while the hot running temp pressure is supposed to be around
5.1
> bar. you see the vast difference between the cold and warm pressures? he
> insists that this is the problem. he says that if i replace my control
> pressure regulator, my overall system pressure will stabilize and things
> should be close to perfect again. however, after all of this pressure
shock
> to my fuel system, i may need to add or remove a couple shims on my
primary
> pressure. this weekend i'm borrowing a fuel pump and CPR from a couple
kind
> DML'ers and i have a feeling i will have a few more questions answered
this
> weekend... and i'll be sure to post to the list what happens.
>
> if you or anyone else have any ideas, let me know.
>
> Andy
>
> Soma576@xxxx
> 1982 DeLorean DMC-12 VIN#11596
> Fargo, ND 58102
>
>
> [Non-text portions of this message have been removed]
>
>
>
> Before posting messages or replies, see the posting policy rules at:
> www.dmcnews.com/Admin/rules.html
>
> To address comments privately to the moderating team, please address:
> moderator@xxxx
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>