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MrMoody
Free range slave
Premium Member
join:2002-09-03
Smithfield, NC
Netgear CM500
Asus RT-AC68

MrMoody to ironweasel

Premium Member

to ironweasel

Re: Bad fuel pressure regulator?

said by ironweasel:

I'll see if I can fashion something up to block the return at the regulator and see what the gauge says.
I don't know if I'd do that, the pressure buildup might damage something else.

Test the regulator by opening the return line into a container, turn the key on for a few seconds (fuel will flow out) and then see if it continues to drip after the key is off.
scrapir
join:2003-12-20
Fond Du Lac, WI

scrapir

Member

Does this car have the 3.1L motor? I've seen the regulator's leak internally causing the leaking fuel to be sucked into the vacuum line. The only way I've checked and verified this being the problem was to pull off the upper plenum and take of the regulator and turn it upside down. If it leaks anything out the vacuum line it's bad. Should be able to find a new one for under $100.

ironweasel
Weezy
Premium Member
join:2000-09-13
Belen, NM

2 edits

ironweasel to MrMoody

Premium Member

to MrMoody
I'll give that a shot if I can find a length of hose that has a diameter that'll match the return line port on the regulator.

Scrapir, it's the 3.8L (232ci Buick) engine.

Edit:

Hooked up some spare rubber vacuum line to the fuel return line and turned the ignition ON. Upon doing so, a steady stream of fuel came out and into a container I had on the groud.

Started the engine and let it run for approximately 2 minutes and then turned it off. After shutting the engine off, fuel continued to flow out of the return line.

The flow, however, dissipated quite quickly and stopped entirely within about 30 seconds.

Anyway, I was reading up on AllData (I purchased a subscription for this car back in September) in regards to the fuel system operation. It noted that a fuel injector is considered faulty if it sprays fuel.

That leads me to another question:

When I first turn the ignition on, the injectors all open up. I'm assuming that this is the "priming" shot of fuel to start the engine, correct?

I haven't noticed the injectors dripping / leaking / spraying at any other time other than when the ignition is first turned on though...so I'm still rather dumbfounded at where the fuel pressure is going.

Edit #2:

More reading on AllData.
Performed the fuel injector leakdown test (jump the fuel pump prime port to B+ with the fuel rail removed) and none of the injectors are leaking.
scrapir
join:2003-12-20
Fond Du Lac, WI

scrapir

Member

Looking at the return line at any point is there a rubber section you could pinch off? Make sure it's not hard plastic.

ironweasel
Weezy
Premium Member
join:2000-09-13
Belen, NM

ironweasel

Premium Member

said by scrapir:

Looking at the return line at any point is there a rubber section you could pinch off? Make sure it's not hard plastic.
Negative.

Both the supply and return lines are nylon / hard plastic in the engine bay and at the fuel tank. Everywhere else is steel tubing.

I think I may see if I can fabricate something out of the old parts I have laying around from when I changed the fuel pump / sending unit out.
scrapir
join:2003-12-20
Fond Du Lac, WI

scrapir

Member

Actually what you could do if it has the quick disconnect lines under the hood is take the return line off and find some fuel hose and clamp it on the return line and pinch it off that way.