Date: Sun, 24 Dec 2000 16:36:08 +0000
Reply-To: Mark Keller <kelphoto@ISLANDNET.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Keller <kelphoto@ISLANDNET.COM>
Subject: Re: fuel pressure
Content-Type: text/plain; charset=us-ascii
Hi J,
Essentially what happens is the fuel system is supposed to stay
pressurized after the fuel pump runs for its intial second or so. If a
check valve is bad,fuel pressure can't build up and then the fuel coming
through the injectors isn't atomized and hard starting results.
There are four injectors, each must seal, and two check valves, one at
the fuel pump and one at the pressure regulator. The check valves are
likely to fail, with no particular preference to either one.
You can trouble shoot with a pressure gauge at the tee fitting used to
bleed air from the system remove the screw, BTW be aware that gas may
squirt a little here; if it does it means the system had pressure on it,
but run the test anyway. Have a helper turn on the key, watch the gauge
for pressure it should hold; if it doesn't position a pair of needle
nose pliers on the hose leaving the pressure regulator, turn the key and
pinch the hose closed immediately after the pump stops. If the gauges
holds pressure or the loss of pressure is slowed the regulator is the
problem. If not pinch the hose just before the Tee fitting. If you still
don't have pressure try pinching both just after the pump stops running.
If this hold pressure both check valves have failed which was my
particular case. I might note that my van only had the large metal fuel
filter on it after the fuel pump. I've since learned that a "pre"
filter is supposed to be installed before the pump, I guess to keep
trash from ruining our check valves. I still haven't put this pre
filter on, but it's on my list.
I have "restored" a pressure regulator to functioning by pinching the
hose from it to the gas tank and watching the pressure on the gauge go
to about 75 psi then releasing the pinch. Doing this a couple of times
and my regulator worked until I replaced it a couple of weeks later.
I'm told that this clears some obstruction on the valve.
Sincerely,
Mark Keller,
91 Carat.
JCarp2001@aol.com wrote:
>
> Mark, I am having similar problem, only when the eng. is cold.
> I prime the fuel system three times, and it starts just fine.
> Do you think I should put a pressure gauge in the system?
> Thanks for your help,
> John C.
> SLC, UT
| 
