fuel pressure regulator bench testing

[cauzomb]

I have two old used pressure regulators, one is from a late model N/A with bolt on/o-ring seal and has been in use for about 5 years being connected with an adapter, to a barbed outlet on the rail via a rubber hose. The other uses ball/threaded seal and has been stored since I got it, they are both rated at 2.5bar, factory 944 parts..

I have adapted the threaded one that has not been used for atleast a few years, to barbed connection and connected it to the fuel rail end, then tested the fuel rail and injectors for leaks, things were normal with the old FPR but the injectors were all leaking from the pintles.. While watching the filler guage as I add air via the tire filler. the regulators open at about 36 psi and allow air to pass, when I close the filler valve, the regulator closes and holds pressure, with only a small bubble slowly forming from the return barb.. The guage reads just a tad over the 36 psi mark and takes a while to drop pressure down to about 20psi.

I connected the FPR that I had been using for several years, and repeated the test.. The regulator that has been in use for several years leaks down from 36 psi to 0 psi in about 4 seconds.

The inside of this leaky regulator is very clean, the metal inside the passages on the fuel side is very brite, but not reflective, it looks almost like it has been acid etched. The fuel pressure regulator that has been stored looks like normal old metal inside, not rusty, but not "new"

All 4 fuel injectors that have been in use and the FPR that was used with them, for several years, are all leaking..

The injectors don't leak that much, but shouldn't be leaking..

The FPR leaks way too much pressure to keep the pressure up in the rail after shut down; leaking pressure too quickly=hard to start the car, have to crank it over longer till the pump builds enough pressure in the rail; and the leaky regulator, maybe incorrect "low" running fuel pressure by maybe a couple psi?

I was doing these tests to trouble shoot the engine running rich, thinking I had clogged leaky injectors, I ran a tank of fuel and a bottle of injection cleaner, but the problem was already there before running the additive, and didn't change, so with the recent test results, I can't help but think that the fuel I have been using (premium pump gas) is either corrosive, or conductive, causing the leaky injectors and the echted look in the FPR via acid corrosion, or galvanic corrosion?

The tops of the injector bodies near the 0-ring seal that ride next to the fuel rail also appear to have been etched, almost look bead blasted.

The FPR and the tops of the injectors see more fuel than the injector pintles, and don't have the constant opening and closing against a solid surface like the pintles, so the injector pintles probly "wear in" but they still do leak, and shouldn't be leaking..

So something is UP with the fuel that I have been using?

Some fuel vendors add alcohol..

I noticed the car experienced poor running, and alot of extra steam in the exhaust when I get fuel from 76 or chevron. Particularly bad running when I get fuel from the chevron station, lots of steam and the car doesn't even want to idle.

There's a sticker on the pump at the 76 station that says contains ethenol or something like that... Could be they have alot of water and alcohol in their fuel making the fuel slightly conductive, causing galvanic corrosion?

Car runs better when I get fuel from shell, V-power premium, less steam in the exhaust, easier to start etc.

Thinking about this some more, some other things that come to mind.. I am now worried about the condition of the inside of my hard/metal fuel lines and the fuel pump and anything else in prolonged contact with the fuel, like the tank.

If I probe the fuel with an ohmeter, or PH test? what results would be considered as contributive to either galvanic or acidic corrosion? a low PH=acidic, high conductivity value = galvanic?