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Subject: RE: FI problems > On 29 Apr 2001, at 0:59, Charles L Navarro wrote: > > > The reason the pressure leaks down is not because there is not a > big enough accumulator, but because there are leaks. A larger > accumulator will hold the pressure up longer, but if there are leaks > the pressure will still eventually fall to zero. Will you be satisfied if > your hold up time goes from 1 hour to 6 hours? In most cases I > don't think you will notice the change. > I work for a company that builds fuel system components, mainly fuel pressure regulators. (Mahle-Parr Filter sytems) We make most of the fuel pressure regulators used in the market today. The biggest problem we worry about is "leak down". This can be caused by many things. For us, it is usually the regulator not sealing off completely. This is caused by contamination or damage to the seating area. The other reason will be a small leak in the diaphram in the diaphram in the regulator. The VW factory proceedure for finding the culprit, is as follows. 1. Attach a pressure guage to the fuel rail. 2. Build pressure in the fuel system by turning the key off and on a few times. 3. While watching the pressure, start pinching hoses, starting at the hose from the RH injectors to the regulator. VW has a clip that does this, but you can use vise grips. Don't pinch the hose to where it is crushed, just closed off. If the pressure holds while this hose is pinched, the regulator is leaking down. 4. The next would be the hose to the cold start valve. Then the hose across the top of the engine, etc. Work your way back towards the pump pinching the hoses. When you find the hose where the leak stops, the last item isolated is your culprit. The check valve in the pump is a known culprit. I am using a Ford fuel pump on my T-3, and it does not have a built in check valve. Therefore, I have to prime my system everytime I start it. Good luck, Russ Wolfe russw@classicvw.org http://www.classicvw.org/ ------------------------------------------------------------------- Unsubscribe? mailto:type3-request@vwtype3.org, Subject: unsubscribe