

| 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 > . >
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