Fwd: Fuel pressure issues

jesper moreau jesper5ktqm.audi at gmail.com
Fri Jan 7 09:15:49 EST 2005


Yes yes, well one thing I do know is that there is no fuel line
blockage. I removed the "fuel headers" (lines from engine compartment
to accumulator area) and flushed them and then blew them out with
130psi of air. Clean and clear as a bell. Plus that is a brand new
accumulator with new Flexi high pressure lines. My new fuel pump
arrives today. I origionally had it in the plans to be replaced
anyway, but it turned out to be earlier than expected.

I will install the pump today and test pressure at the same point I
did yesterday and note any differences to all of you. I have a feeling
it will be very different!
Stay tuned!

P.S. If anyone needs a  new OEM bosch pump for a 88 5KTQ... I got mine
from German auto parts (adirondack auto brokers) for $183 and that
includes the check valve.

Jesper Moreau
'88 5KTQ rocket
'86 5KTQ stocket

---------- Forwarded message ----------
From: SJ <syljay at optonline.net>
Date: Fri, 07 Jan 2005 00:31:19 -0500
Subject: Re: Fuel pressure issues
To: jesper moreau <jesper5ktqm.audi at gmail.com>
Cc: quattro at audifans.com



Oh yeah, sounds like a bad fuel pump.

However, you may have a blockage in the lines. Doubtful though. after so
many seconds, with no fuel flowing thru the system, you should get full
pressure that the pump can deliver even if you do have blockage.
Put a hose on the outlet of the fuel filter and put other end of hose into a
bucket. See how much fuel gushes out.

Or, you may have low voltage at the fuel pump. Check the voltage at the pump
while its running.

System pressure should be 90 PSI. It used to be lower on previous years. I
forgot when they changed over to the higher pressures.
System pressure is produced by the pressure regulator. Which means you need
more that 90 PSI to begin with. If the regulator sees any pressure less than
90PSI, it just shuts off and system pressure will be whatever the pump is
capable of putting out.

I would think that the fuel pump, with line blocked with pressure gauge,
should put out more than 100PSI.

SJ

----- Original Message -----
From: "jesper moreau" <jesper5ktqm.audi at gmail.com>
To: <cody at 500tq.com>; <David.Payne at brinksinc.com>; <syljay at optonline.net>;
"Tony Hoffman" <tfh400036 at yahoo.com>; "Denis" <sparkplugvw at hotmail.com>;
"list submissions" <quattro at audifans.com>
Sent: Thursday, January 06, 2005 2:03 PM
Subject: Fuel pressure issues

> Haudi again, I finally just received my Bosch Cis test kit. Just to
> reacquaint you all, I cannot start my car after having spent the
> entire spring summer and fall rebuilding my '88 5KTQ. I have found I
> am not creating enough fuel pressure to push fuel through the
> injectors. I do have spark. No injector-side air leaks.
> So, I was excited and went out today in the cold drizzle to at least
> check one fuel  pressure test point. Maybe out of order, but I went
> for the banjo connection at the fuel filter. (new filter and
> accumulator and accum. attachment lines mind you) so I figured if my
> fuel pump is any good at all I should get a good reading.
> So, I connected the gauge in-line at the engine side of the fuel
> filter, pulled the fuel pump relay, turned the turned the keys to
> "on", verified a perfect 12V at the battery, ran a jumper from it to
> socket 52 on the relay panel... the fuel pump kicked in, and in about
> 15-20 seconds it leveled off at a reading of about 36-37 psi
> at that point I figured alas, my fuel pump is the culprit. would
> anyone agree, or did I do anything wrong? I know it takes somewhere
> around 60-62 psi to spray an injector. I also know the system should
> register around 78-80 psi.
> any feed back is much appreciated
> thanks again!
>
> --
> Jesper Moreau
> '88 5KTQ rocket
> '86 5KTQ stocket



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