<VV> Followup to engine cutting out

[Larry Forman]

Hi Anil,
Many thanks for posting this.  I know that our club President has personally repaired at least two fuel pumps by just staking the valves.  I suspect it is a common failure mode for failed pumps.

One trouble shooting approach to help isolate these failures is to have a special test "T" connector in the output fuel pump line and attach a fuel pump pressure gauge.  Then monitoring this pressure and seeing if the drop in pressure corresponds a short time later to the missing or cut out condition would positively identify the problem to fuel versus ignition issues.  Remember that running this fuel pressure line into the passenger compartment is very dangerous in case of any fuel leak.  This should only be a temporary test.  Alternatively, a much safer route would be to use an electronic pressure gauge and that could be left in permanently with no fuel plumbed outside of the engine compartment.

Regards,

Larry
----- Original Message -----
From: "Anil Mittal" <anil@anil.com>
Date: Wed, 1 Sep 2004 10:51:20 -0400
To: virtualvairs@corvair.org
Subject: <VV> Followup to engine cutting out

> Hello All,

>   I think 1 of two things could have been happening:
> 
>     The valve fell out of the bore the pump and the pump would stop
> pumping, then somehow with cranking the valve would pop back in and
> the pump would pump again.
> 
>     The bore would expand around the valve when the engine/pump got
> hot which would not allow the check valve to work efficiently and the
> pump would not pump. Then the pump would cool/contract back around
> the valve and the pump would pump again.
> 
>    From what I have read on the list over the last 10 years the only
> failure mode of a Corvair Fuel Pump is tearing of te diaphram and
> leaking of fuel. I have never heard of this type of failure. Has
> anyone seen this? BTW, the pump is from one of the Major Vair
> Vendors. 

> Anil