frequency valve, 200tq '89 MC2

[Konstantin Bogach]

> Checking the car I noticed that FV buzzes not constantly but =
> periodically (on idle), with 1-2 seconds breaks when it is silent.  On
=
> my 200tq '89 MC1 it buzzes constantly. Is it normal on MC2 (MAC-14)?
At =
> output test FV  sounds ok.

No, it's not normal.  I suspect it's running all the time and struggling

with cavitation _most_ of the time - the quiet periods are when it's
not having trouble.  You'd need to attach a fuel pressure gauge to the
system pressure to be sure.  First suggestion is to check the fuel pump
screen and remove it if it's clogged with brown stuff.

--
 Phil Payne
 http://www.isham-research.freeserve.co.uk/quattro
 Phone +44 7785 302803   Fax: +44 7785 309674


Phil,

Thanks for your response. But I did not undestand something: do you mean
that I should not hear FV when everything ok and buzz means some problem
(cavitation)?

Konstantin