pressure testing fuel accumulator

[lazyeyedog]

First of all, thanks to everybody for your generous responses to my first post "3.0 hot start problem".

I've gathered that the first logical step would be to pressure test the fuel accumulator. Once removed, can I accomplish this with air pressure, (what psi?) and what port(s) should I pressurize/ plug, and for how long should it hold pressure?

Thanks again for all your responses

[rusnak]

There is a really nice Bosch CIS fuel pressure kit on the Harbor Freight website, and on Pelican too. You need to check the system pressure after a few mins, and again after 30 mins I think. Been a while since I looked at the Bentley manual.

[boyt911sc]

Lazy,

You need just a low air pressure (10 - 15 psi) to test a fuel accumulator. A bicycle pump could be used to do the test if you don't have an air compressor or a brake fluid bleeder (Motive).

For your three-port fuel accumulator, plug one port (top) and inject air to the other port (top). If you don't have a pressure gauge set-up, here is a very simple set-up.

Install a small plastic tubing about a foot long to the bottom port (drain) and submerge the other end of the plastic hose in liquid (water). When the upper chamber is pressurized, there should be no sign of air escaping through the plastic hose. This means that the diaphragm inside the fuel accumulator is good and not leaking. If bubbles are observed during the test, this is a sure sign that the FA is leaking. HTH.

Tony