My main pump is making noises like there are bees inside. I think it's telling me to prepare to replace it. There is one on Ebay I could bid on. Anyone out there have a main fuel pump in their garage that they would like to sell?
--
Simon 80 240 296k 17 years.

Your main tank buzzing like that can be a sign of its imminent failure, but more likely it's a sign of either a bad intank pump or a deteriorated hose that connects it to the main pump (it's a couple inches long, attached to the intank pump - if there's a crack in it Bzzzzzzz).

With the engine running open up the gas cap and listen for the healthy whirring of the intank pump. If you hear nothing or a grindy, whiney uneven sound, replace the intank pump. If the intank pump sounds good check the 700-900 FAQ or your Bentley manual for procedures to measure the flow rate and/or pressure coming from the intank pump. Also check your pumps for current draw before you suspect them.

And you might check into your fuel pressure regulator if you have one. That also can cause your main tank to complain.

Before you replace that awfully expensive main pump, you'll want to disqualify these other more commonly failed components as culprits.

Thanks for the info. I've tried listening to my fuel tank. My neighbor is waiting for me to talk into it now. There is no noise at all so I assume the in tank pump is not working. Its been like this for a few years as I remember it used to be quite noisy (probably just before it quit. But I'll definitley check the hose. Sounds more like a kazo now that I think of it. As for expense the main tank unit on Ebay will end up at about $60 so it is not too bad. I'll pull the whole in tank unit off of one at the wreckers.
--
Simon 80 240 296k 17 years.

I forgot to mention if you hear nothing when you listen for the intank pump, you should make sure you are getting power to it before you decide to open it up and replace it. You can check power at the fuse, and at the wiring going into the pump. A simple test light would tell you whether or not the intank pump is getting power. I forget which color is which going into the intank pump unit, but it won't be hard to figure it out.

Put the test light on it and there is power getting to the pump. I've ordered the replacement from IPD. Actually it is the upgraded pump. It is a higher capacity pump. Should improve my 1/4 mile times!
--
Simon 80 240 296k 17 years.

"Fun With The Tank Pump Fuse"

The Tank Pump Fuse can be very helpful — if you have a 200 series Volvo, and a Test Light or Digital Multimeter.

Depending on the Fuel Injection system, the Tank Pump Fuse will be or #4 (LH 2.2, 2.4) or #5 (K-jet, LH 2.0, LH 1.0)

When looking at the fuses, the unfused or "Hot" side is on the left, as shown below.

Hot (+) side —*—<<—(FUSE 4/5)—>>— fused (–) side goes——> to the Tank Pump

* Voltage at (or applied to) the Hot side goes *DIRECTLY* to the Main Pump. (This point SHOULD normally be at +12V whenever the FI Relay is energized.)

At the Fuse Holder, you can:

• Verify Fuel Injection (aka Fuel Pump) Relay operation. (Look for +12V on Fuse 4/5 input while cranking)
>>>• Test ("hot wire") either Fuel Pump (or both) Get +12V from fuse 6 input contact <<<
• Use the hot wire as a No-Start diagnostic, or to run pumps for pressure tests, etc.
• Measure each pump's Current "draw" (requires Ammeter function, 10 amps max is OK)
• Test and measure the O2 heater resistance (LH 2.4)

--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.