SGT MAC

I have sprung a gas leak out of this part (the round one with the cross on it and lines coming from 10 and 2) I thought it was a regulator of some kind, but none of the pictures on any fuel system part I find match up. Can someone help me identify it, and find someone who carries it, or a work around? 1990 Camaro RS, 3.1 V6. The part is right under the throttle body.

W.E.G.

I don't know for sure what it is, but found a clearer pic at https://www.thirdgen.org/forums/v6/4...3-1l-fuel.html

Could it be some sort of check-valve for the fuel return line?

SGT MAC

I think it is some kind of regulator. Local junk yards don't have a 3rd gen right now, so I may have to wait it out. Can't find any matches online. I guess I could take out a loan and go to the dealer...

scooter

iTrader: (11)

Unlikely that it will still be available at the dealership, but it's not a regulator, that is the round black thing in W.E.G.s picture

SGT MAC

That's what I thought too. My only hope is that the dealership has an exploded view of the fuel system that would call out the part name and number.

Tuned Performance

iTrader: (92)

I don’t think it’s a serviceable part. I think it’s a pulsator to help prevent pump noise from the fuel line.

SGT MAC

W.E.G.

Evidently, most cars are equipped with some sort of fuel line anti-pulsation device.

Google shows that guys on the Corvette forum are replacing leaky pulsators with a section of rubber fuel hose. They claim the rubber hose does a sufficient job of mitigating the noise, emanating from the fuel line, caused by the injectors slamming shut.

I believe the later-model third gen cars installed this gizmo up front near the fuel rail. Older fuel -injected third-gens have the gizmo leaking back in the labyrinth somewhere near the fuel tank bunghole. My 88 stinks of fuel to high heaven back there any time the tank is more than quarter-full. I wonder if my pulsator is leaky too? Maybe we drink at the same bars.

W.E.G.

When you carve it out of there, will you please disassemble it, and let us see what the innards of a fuel pulsator look like?

SGT MAC

Oh, heck yeah-I'll post as soon as I cut it open.... I might try the rubber hose tonight and see how it goes. Any theories on failure modes if it doesn't work?

W.E.G.

I honestly don't think you will fail.

You may be able to find a piece of formed "elbow" (90-degree or 60-degree) type rubber fuel hose so you don't have to kink piece of straight hose, or have to try to bend the existing metal lines to accomodate a piece of rubber hose. As always, measure twice. Cut once.

Make sure its fuel hose, and not any other type of hose. Any other type will melt when exposed to fuel.

Assuming you achieve tight connections, worst thing that I think can happen is you have some sort of tapping or buzzing noise (injectors causing rhythmic sound) in the fuel lines that was not there before. My car has so many creaks, groans and squeals, I cannot imagine it ever being quiet enough that I would be bothered by some small, persistent, identifed sound in the fuel lines.

On the subject of tight connections, remember, your connection has to hold up to 50 PSI pressure. So, allow for lots of overlap of your rubber hose over the fuel line. Don't use too-skinny hose clamps, and don't try to join nubbin-to-nubbin. A little overkill in the overlap is probably a good idea when you are securing your fuel line with hose clamps. In a perfect world, you would bubble-flare the ends of the metal lines, to reduce the chance of fuel pressure blowing the rubber connector off. If you want to remove the hard line, and have at it with a flare-tool, you will be our hero of the pusator-elimination campaign. Otherwise, I'd probably just double-clamp my rubber at both ends, and dive in like a boss.

W.E.G.

If you google "molded fuel line," all sorts of options for buying rubber fuel line with molded-in bends pop up.

Tuned Performance

iTrader: (92)

Use high pressure fuel rated softline. I would double clamp it as well.
I think it’s 3/8 in size .

SGT MAC

Alright, so I cut the piece out last night. I cut the piece off right before the longest parts without a bend, then used 1 foot of high pressure fuel line to bridge the gap. On the passenger side, I was able to overlap by about 6 inches, about 4 inches on the drive's side. I used two hose clamps on each side, but I may replace them with some crimp on clamps later, for looks if nothing else.


I used a sawzall to cut the line in the car. Almost took a die grinder out, but used my brain for once..
Had to file this one off and remove the dent in the line.
3/8" High Pressure Fuel Line. Hopefully this has enough flex in the sidewalls to dampen the pulses, as needed.
Used about 12" of line. This made the curve a big enough radius that it shouldn't get kinked.
I had my son cut it open, nothing in there but a little bit of old deposits.

SGT MAC

If this is the pulsator, I'm not sure how it works. The walls seem too stiff to flex with that little pressure difference. There is no way to either trap, nor meter air into it to let it act like a surge tank, and with fuel being in the liquid state/non-compressible, the volume should not be able to change, unless you pull a vacuum and boil the fuel. Maybe the turbulence caused by the entry and exit angle make it act like an inductor. like a little whirlpool? Maybe the fuel spins around in there saying "look kids, Big Ben"...

RBob

iTrader: (1)

Wrong hose and wrong clamps. Hose needs to be SAE 30R9, and need to use fuel injection hose clamps.

RBob.

OrangeBird

iTrader: (1)

RBob is 100% correct , ANYTIME you replace flexible fuel injection hose it must be with hose that is rated for fuel injection systems , and use the proper clamps as seen in my two enclosed photos . And before anyone asks , yes indeed this goes for the return line as well , lest the next bonfire you attend be the one under your own hood ! Now you really don't need to double clamp each end like a fire paranoid old man (me ) , but the right hose and hose clamps really are a must have here .

Oh , and , yes indeed that stupid can is nothing more than an "expansion chamber" of sorts , put there in the later cars to eliminate customer bitching about "gurgling" sounds of the fuel being returned to the tank under certain (deceleration mostly) conditions . My 89 2.8 was not factory equipped with such nonsense and to be honest I've not once heard this dreaded gurgle that the offending part is supposed to "cure" .....

W.E.G.

Very informative thread.

Google search on difference between SAE 30R7 and 30R9 hose:
https://www.google.com/search?q=diff...+sae+30r7+30r9

Thanks for carving-open that gurgle-can.
Buy that boy some ice cream!

SGT MAC

Thank you for the advice. In all my time under the hood, haven't messed with fuel injection much. This forum saved the same car from an early grave in 2009 when I had a dead injector, causing the rest of them to flood. I must have put 40 hours into that problem before I found a ~12 page thread on here, all the time thinking "if this was a 1974 model, I'd set the points, check my floats, and be back on the road..."
I'll hit up NAPA on my way home and post some corrected pics when I get the chance.