[T3] FI Fuel Pressure Regulator Post Mortem

["Jim Adney" <jadney@vwtype3.org>]

Keith Park was good enough to send me a Fuel Pressure Regulator which 
had been sticking such that he had fuel pressure much too high when 
he first started his car.  He speculated that it might have been 
filled with some kind of crud (that's the scientific term) which kept 
it from working properly.

I cut it apart in a lathe and found that there was nothing wrong with 
it that I could see.  When I cut through the rolled over seal, the 
unit burst apart, scattering its guts everywhere.  I was lucky enough 
to find everything except the spring.  Serves me right; I was just 
wondering if I should set up the tailstock to restrain the parts when 
it cut through.  I spend more time searching for parts than I would 
have spent doing it right in the first place.

There were no extreme accumulations of any kind on the fuel side of 
the diaphram.  There was quite a bit of corrosion on the air side, so 
I suppose that if Keith had his problems in freezing weather there 
might have been water here.  That COULD have produced his symptoms.

I found the inside construction to be more complicated than I 
expected.  The regulating valve consisted of a steel tube end with a 
polished surface and a facing steel polished plate which is swivel 
mounted with a spring to take up any free play.  All the parts were 
still in good shape, although the diaphram shows its age.  I assume 
that exposing one side of the diaphram to gasoline will probably 
soften it up.

If this regulator had been out of service for a long time it is 
possible that Keith's problems had to do with the dried out diaphram. 
That seems a little unlikely since the diaphram is thin and should 
have come into equlibrium with the gasoline in a couple of days or 
less, and I suspect that it took Keith more time than that to find 
the source of his problem.

So, Keith, would you like to have your parts back so you can see what 
they look like?

Jim
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Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
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