Fuel Accumulator 1981 240DL Wagon

_____ Hello All,

Am restoring a 1981 Volvo 240DL Wagon. Replaced a failed in-tank pump, and the main pump under the car. The fuel accumulator sits right next to the pump. When i installed the new pump i noticed that some fuel leaked from the vent nipple that is connected to the fuel tank with a small rubber hose. Am i correct in assuming that the diaphragm in the accumulator must have a hole in it and that it should be replaced? Or is it normal to see some fuel at the vent nipple? The system delivery pressure is steady at 70 psi right after the filter in the engine bay.

Regards / John

Reply to
jch
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Yes, time for a new accumulator. There should be no fuel there.

Reply to
Mike F

Thanks, Mike. I was afraid of that. A friend, who has a DeLorean sports car with a 6 cyl Volvo engine, gave me his old accumulator. The engine uses an eCIS, which is virtually identical to mine, but has a constant idle speed motor and ECU. The accumulator is bigger in diameter, and a bit longer. I will try that one and assume that the pressure delivered to the filter will be the same. Once i put the gauge on it, and i read the 70 psi i get now or higher, i will be happy.

/ John

Reply to
jch

The accumulator is just a "shock absorber" for fuel pump pulses. Pressure is set by the regulator, and the pumps ability to meet that pressure. Having an accumulator too big won't hurt anything, having one too small might, but I doubt it. As long as the fuel connections are good (don't leak) and you can properly mount it physically (so it's supported and the fuel lines don't break) then you won't have any problems.

Reply to
Mike F

In article , snipped-for-privacy@nowhere.com says... _____

The function of the accumulator is to provide enough pressure on the fuel coming from the pump to force any air bubbles to dissolve in the fuel and to maintain a small pressurized reservoir of fuel to keep the lines charged all the way to the injector nozzles so if the car stalls there is enough residual pressure to allow it to start right back up. If the weather is very hot it keeps the fuel from boiling in the injector lines. If the diaphragm is ruptured, i.e. if there there is even a hint of fuel smell from the rubber pipe that returns to the tank, then the car most likely will require an extended cranking time to start (but may start fine) and create no power for a good 60 seconds before you can pull off, even though the engine seems to react normally to accelerator pedal pressure.

The newer style accumulators have no vent nipple on the back. A retrofit requires that the vent tube from the tank be capped or fuel will siphon out when the tank is filled and the fuel expands while sitting parked in hot weather.

Bob

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