Skip to main content
Gerry | Vanagon
Checking account...
← vanagon.com home · Continue the discussion in the forum
Subject:Re: Residual Fuel Pressure: hold for 1 hour?
From:JRodgers
Date:Tue, 4 Mar 2014 04:05:23 -0600

Neil,

I Have the same issue on one of my '88's. Hard start when warm. When
cold starts immediately.

I too would like to know what's with that!

John

On 3/3/2014 9:46 PM, Neil N wrote:
> 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
> .
>