Fuel Accumulator Clamps

[kings1527]

There are three connections on the fuel accumulator. Two on one side and one on the other.

On the side that has the single connection, should there be a clamp there? Mine is just inserted without one and I've seen others the same way. But I've also seen others that do have a clamp. My hose looks to be original.

Thanks!

[Rich]

No clamp req'd on that hose. It's the breather-vent hose leading back to the fuel tank. It normally has no fuel in it and is at atmospheric pressure, opening as it does to the tank. When the accumulator diaphragm fails this hose safely routes the small flow of leaking fuel to the tank. At low pressure.

PS, this design feature keeps many accumulator failures from being more rapidly diagnosed. When the internal diaphragm "leaks" the leak remains (safely) unseen because of this fail-return hose.

[David T]

No clamp req'd on that hose. It's the breather-vent hose leading back to the fuel tank. It normally has no fuel in it and is at atmospheric pressure, opening as it does to the tank. When the accumulator diaphragm fails this hose safely routes the small flow of leaking fuel to the tank. At low pressure.

PS, this design feature keeps many accumulator failures from being more rapidly diagnosed. When the internal diaphragm "leaks" the leak remains (safely) unseen because of this fail-return hose.

Actually it has more than atmospheric pressure, it is tee'd into the return line from the Fuel Distributor and the Primary Pressure Regulator is always dumping the excess fuel back to the tank. It is not a high pressure line but there is some pressure and a good amount of fuel flow. Even if the accumulator is not leaking.

[kings1527]

No clamp req'd on that hose. It's the breather-vent hose leading back to the fuel tank. It normally has no fuel in it and is at atmospheric pressure, opening as it does to the tank. When the accumulator diaphragm fails this hose safely routes the small flow of leaking fuel to the tank. At low pressure.

PS, this design feature keeps many accumulator failures from being more rapidly diagnosed. When the internal diaphragm "leaks" the leak remains (safely) unseen because of this fail-return hose.

Thanks for that info, Rich. I didn't describe the location real well but I think you know what I was getting at. It's actually the hose that's directly above the hard fuel line (on the side where there are two connections). Not the single connection side as I originally described. I'm back to thinking I have an accumulator problem but wanted to make sure I wasn't losing rest pressure out of that line because of a missing clamp.

Thanks again!

[kings1527]

Actually, now that I think about it, that one will definitely have fuel in it.

I'm thinking it should definitely have a clamp? The one directly above the hard line?

[DMCMW Dave]

Actually, now that I think about it, that one will definitely have fuel in it.

I'm thinking it should definitely have a clamp?

I would.

[kings1527]

Thanks Dave. This is all PO stuff. I haven't touched the accumulator since I've owned the car but I have seen pics without a clamp there. And as far as I know, it's just a barb connection. I'm glad it's held itself on! I put a clamp on it to see if that solves my rest pressure issue, which I'm guessing it probably won't.

[Rich_NYS]

Here's a pic of mine from a few weeks ago, does yours look similar? There were no leaks at that time, but I planned to change them anyway. Last week when I ran the pump I developed a leak in this area, so I'm guessing the extra bit of pressure got to it.

I plan to clamp mine wherever I put a hose.


24935

[kings1527]

Here's a pic of mine from a few weeks ago, does yours look similar? There were no leaks at that time, but I planned to change them anyway. Last week when I ran the pump I developed a leak in this area, so I'm guessing the extra bit of pressure got to it.

I plan to clamp mine wherever I put a hose.


24935

Yup, mine is the exact same setup. It's amazing to me that the lower left connection doesn't have a clamp (nor does mine). I put a clamp on it just now and I'll test the rest pressure again to see if that was the source. But it seems to me, at least for safety's sake, that you'd definitely need a clamp there. I've seen several cars, even cars that have been serviced at DMC service centers, that don't have a clamp there and I seriously doubt it was an oversight.

[Rich_NYS]

I've seen several cars, even cars that have been serviced at DMC service centers, that don't have a clamp there and I seriously doubt it was an oversight.

From what I hear, it's a special type of hose, fitting and/or special process to put it on. Someone else here can probably fill you in on the details, I'm new to the "no clamp" type of hose fitting.

[Rich]

No clamp req'd on that hose. It's the breather-vent hose leading back to the fuel tank. It normally has no fuel in it and is at atmospheric pressure, opening as it does to the tank. When the accumulator diaphragm fails this hose safely routes the small flow of leaking fuel to the tank. At low pressure.

PS, this design feature keeps many accumulator failures from being more rapidly diagnosed. When the internal diaphragm "leaks" the leak remains (safely) unseen because of this fail-return hose.

Based on your later description that the line in question is one of the two lines on the one side of the accumulator it is one of the high pressure (~75PSI) fuel lines, not the low-pressure leak-return line that is by itself on the other end of the accumulator.

Like Dave said, clamp it.

[NightFlyer]

In Rich's picture, it's the stock/OEM hose from the factory, which was originally thermocoupled/crimped onto the fitting - much in the same way that the banjo fittings on all the engine bay fuel lines are not clamped to the hoses either.

Won't hurt anything adding a clamp, but as there wasn't any fuel leaking, it's also probably not the source of your rest pressure issues.

As you still have the stock/OEM hoses in the accumulator cubby, I'm guessing that the accumulator is probably original to the car. Given that you've 1) added an external in-line check valve at the tank, 2) replaced your PPR o-ring, and 3) have your dwell dialed in pretty good, I'm guessing that the accumulator is the source of your current hot-start problem and needs to be replaced.

[kings1527]

Thanks everyone. It definitely looks like it's my accumulator. Like you said, I've ruled out everything else. I have Dave McKeen's RPM relay and it does a great job of compensating for any rest pressure issues, but every once in awhile I'll get a hot start problem. So I took out his relay and put my spare OEM RPM relay in there to test it and sure enough, it was symptomatic.