[urq] Warning about Fuel Pressure Accum.

[SpotatAshleys]

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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