[urq] Warning about Fuel Pressure Accum.

Thu Jan 29 14:50:23 EST 2004

Thanks for all the suggestions;
I'll have time to look at it a bit more at the weekend but just for the
record:

The car is a 1987 WR.
The fuel pump on these does not power up unless the engine is spinning (or
relay contacts bridged)
The engine is 1000 miles old.
Injectors and seals are brand new.
Plugs new and colour is as it should be.
Distributor Cap is 1000 miles old
Plug leads 1000 miles old
Battery is 1000 miles old
Air fuel meter readings suggest warm up regulator and cold start injector
are working fine. Shows rich on start up, declining to stoich as it warms.
When it does fire, small amount of black smoke suggesting rich mixture.

Next tries will be check valve in the pump and the accumulator and when I
can get my hands on the kit a system pressure check . Will also read the
archive as suggested when I get 5 minutes.
When I first ran the car (it had been off the road for 3 years at least) the
fuel pump was noisy. Now it is quiet - any significance or should I just
count my blessings it is not noisy?
Will a coil decline in performance or do they just work/ not work? Just
wondered if could be a weak spark as suggested by on lister?

Whatever, thanks for all the suggestions so far.

All the best

Keith

'87 WR
----- Original Message -----
From: "Jim Haseltine" <jim_haseltine at ntlworld.com>
To: "Patrick Carlier" <p.carlier at pandora.be>; "SpotatAshleys"
<spotatashleys at hotmail.com>; "Ben Swann" <benswann at comcast.net>
Cc: <urq at audifans.com>; <quattroguy83 at yahoo.com>; <quattro at audifans.com>
Sent: Wednesday, January 28, 2004 10:43 PM
Subject: Re: [urq] Warning about Fuel Pressure Accum.

> This should't work on an Ur-q, the fuel pump should only run when the ecu
> thinks the engine is spinning. The way to do it is to put a jumper cable
for
> a couple of seconds across the switched pins in the fuel pump relay socket
> (if the car has the under bonnet fuse box these are the two BIG pins).
>
> Regards,
>
> Jim Haseltine
>
> ----- Original Message -----
> From: "Patrick Carlier" <p.carlier at pandora.be>
> To: "SpotatAshleys" <spotatashleys at hotmail.com>; "Ben Swann"
> <benswann at comcast.net>
> Cc: <urq at audifans.com>; <quattroguy83 at yahoo.com>; <quattro at audifans.com>
> Sent: Wednesday, January 28, 2004 9:20 PM
> Subject: Re: [urq] Warning about Fuel Pressure Accum.
>
>
> > Keith , have you tried this :
> >
> > Turn on the ign key , but don't crank .
> > You should be able to hear the the fuel pump running for a few seconds .
> > Repeat this several times in a row : allow the pump to run till it
> switches
> > of ,
> > switch off the ign and turn the pump back on .
> > This will allow you to build up pressure on the fuel system .
> >
> > If after that the car starts normal or much better , you have either a
> > leaking check valve
> > or a broken accumulator .
> >
> > Pat
> >
> >
> > ----- Original Message -----
> > From: "SpotatAshleys" <spotatashleys at hotmail.com>
> > To: "Ben Swann" <benswann at comcast.net>
> > Cc: <urq at audifans.com>; <quattroguy83 at yahoo.com>; <quattro at audifans.com>
> > Sent: Wednesday, January 28, 2004 8:59 PM
> > Subject: Re: [urq] Warning about Fuel Pressure Accum.
> >
> >
> > > Thanks Ben (and others too)
> > > In an effort to cure the long cranking I replaced all the injectors
> first
> > > but still have the problem hence my questions now about the
accumulator.
> > The
> > > battery is brand new and very good. It always starts (so far) but
after
> an
> > > inordinate time cranking.
> > > It looks like keep replacing things till it starts properly and the
> > > accumulator could be next unless someone has a bright idea.
> > > Thanks again
> > >
> > > Keith
> > >
> > > '87 WR
> > > ----- Original Message -----
> > > From: "Ben Swann" <benswann at comcast.net>
> > > To: <ashleyj.cobain at virgin.net>
> > > Cc: <urq at audifans.com>; <quattroguy83 at yahoo.com>;
<quattro at audifans.com>
> > > Sent: Wednesday, January 28, 2004 5:27 PM
> > > Subject: [urq] Warning about Fuel Pressure Accum.
> > >
> > >
> > > As you mention, when operating correctly, the accumulator should help
> > > maintain the fuel pressure to around 35 PSI after shutoff if there are
> no
> > > leaks in the system.
> > >
> > > The FP accumulator also act as a damper to smooth out pulses/spikes in
> the
> > > pressure.  Analogous to the vertical tube a plumber would install to
> > prevent
> > > water hammer when a faucett is closed rapidly in a plumbing system,
but
> > also
> > > similar to the water pressure accumulator used on well fed systems - a
> > tank
> > > that holds water with a bladder full of air at the top.  The
accumulator
> > on
> > > the fuel injection system uses a spring instead of air to maintain
this
> > > pressure.
> > >
> > > As you allude to a faulty pressure accumulator can cause hard
starting,
> > long
> > > cranking.  I have found more often, a leakdown on the injector side of
> the
> > > system is the problem, and the accumulator is secondary.
> > >
> > > Ben
> > >
> > > [Please excuse my ignorance but what is the precise function of the
fuel
> > > accumulator?
> > > It is supposed to maintain system pressure when the engine switched
off?
> > In
> > > other words could this be my problem with cold starts? Hot starts are
> > fine.
> > > Mixture is not a problem during cold starts, once started. The warm up
> > > regulator is working because the air fuel meter shows it is doing it's
> > job.
> > > The problem is that I have to crank it lots before it fires. Is this
> > because
> > > it has lost system pressure over night and I then have to crank for
fuel
> > > pump to restore pressure?
> > >
> > > Look forward to receiving your thoughts
> > >
> > > Keith
> > >
> > > '87 WR]
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> > >
> >
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