Fuel pump roulette

[David Boyd <john@dboyd.demon.co.uk>]

>One that gets louder when it's hot out or under
>certain conditions is different from one that is getting progressively
>louder.  Also, my understanding is that a later model fuel pump (motorola I
>believe) supercedes the Bosch one at the dealer.  This is supposed to be a
>"better" pump design.  Also about twice the price of the good ol Bosch
unit.
Seems like the newer pump might be money well-spent. Anyone have more info
on this model?
Thanks for the input, Scott.
Phil
'91 200q (probably gonna have its FP screen removed, pronto.)

Phil

BTDT with newer pump, assuming UK and N. American fitments are the same.

The VAG part no. for the newer pump itself is 895 906 091A and this is
listed as OE for the Coupe 89 onwards and the Audi 100 (5000) mid 89 onwards
(although mine is a mid 91 and still had the old type Bosch which I think is
part no 895 906 089).

This replacement pump is of Pierburg manufacture and is smaller in diameter
than the Bosch. It has an around half inch diameter gauze covered inlet for
the tank petrol. It cost about GBP 84 plus 17.5 % taxes from an aftermarket
supplier (German & Swedish, London). No doubt  more from Audi.

To fit the newer pump in place of the Bosch, you do however need a
replacement housing, ie., the nylon casing / external filter in which the
pump sits and which clips into the nylon retaining ring arrangement in the
bottom of the tank. Unfortunately I have mislaid the invoice/part no. for
this, bit from memory you need the casing plus a matching union nut and
washer for the fuel line to pump connection and this cost around GBP 45 or
50 from Audi.

The new Pierburg has an audible slight buzz, but this is only just audible
over the engine noise on tickover. If anything, it has become slightly
quieter after a few thousand miles running. (I once replaced the pump on my
previous Audi 100 with a Bosch and the noise reduction was just about the
same.) This relates to Avants, and I suppose the saloon should be a little
quieter than this.

Hope this is some help.

Regards

David