Date:         Mon, 3 Mar 2014 19:46:35 -0800
Reply-To:     Neil N <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Neil N <musomuso@GMAIL.COM>
Subject:      Re: Residual Fuel Pressure: hold for 1 hour?
Comments: To: "SDF ( Scott Daniel Foss )" <scottdaniel@turbovans.com>
In-Reply-To:  <53153E47.5060000@turbovans.com>
Content-Type: text/plain; charset=UTF-8

Hi Scott.

> Do you normally start the van by turning the key to *ON* ( not start )..
> then listen for the fuel pump to run, aand then shut off...before
> turning key to 'start'  ??

I always turn key to ign. on, listen for pump, look for lights, then
start the engine. The Jetta Motronic engine management primes the fuel
pump *very* briefly. Like 1 second.

Engine cold, it always starts the first time and drives fine. If I
drive it til it is up to temp, shut engine off, then try to start it
1/2 hour - 45 later, (engine slightly warm), it won't start the first
try. It just cranks and cranks. If i keep cranking, it might "cough"
once or worse, barely run, stall, then become really hard to start.
This is consistently repeatable. For some time now, the fuel pump
tends to get quite noisy on hot days so yes. For that reason alone, I
felt I needed to address this.

During todays tests, with engine only partly warm, if I use my fuel
pump relay bypass switch to run the fuel pump for 5 seconds or less,
it instantly pressurizes to 40 PSI. If I shut pump off after the 5
second mark, pressure drops very quickly to zero unless I clamp off
the fuel supply hose. Engine cold, if I run pump for only 1 second
then turn it off, the system holds pressure (residual pressure) just
like it should. All this seems to support the above conditions. I just
can't figure why the fuel pump is behaving like this.

I'm about certain the fuel pump is at fault. Yes I can replace it but
assuming the check valve is at fault, I'd really like to know why it's
behaving this way.



On 3/3/14, SDF ( Scott Daniel Foss ) <scottdaniel@turbovans.com> wrote:

> Do you normally start the van by turning the key to *ON* ( not start )..
> then listen for the fuel pump to run, aand then shut off...before
> turning key to 'start'  ??

> I think you are chasing a mostly non-problem.


--
Neil n

Blog: tubaneil.blogspot.ca

'88 Westy http://tinyurl.com/c8rlw6p

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG *Gas* inline-VR Engine Swap Group:

http://tinyurl.com/d7gd5ej