Fuel pump problems 1992 740 wagon. Help needed?

I'm at a loss what to do. I've got a 92 Volvo 740 wagon. My repairman (not a Volvo man) replaced the fuel pump 5 weeks ago. Two days later, the car wouldn't start and had to be towed back. He claimed the pump was defective and replaced it. The day after I took it home, the car stalled about 3 blocks from my house and had to be towed again. The repairman claimed the hose to or from the fuel pump was leaking. In the three weeks since then, the car has stalled out about every 3rd or 4th day while driving. It's failed to start once after filling with gas and this morning, stalled at a stop sign. In all of these cases, I've been able to re-start it.

Does anyone have any idea what may be wrong? I have a sense my mechanic doesn't have a clue. Each time he's taken it in to replace the pump, it's taken at least three days to get a new pump and replace it. MY 16 year-old son is learning to drive with this car and is already complaining that I should get a new one.

Reply to
piergud
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It could be that the in-tank pre-pump is clogged or failed. That will burn out the main pump. You really need a mechanic who knows what they are doing with Volvos. The worst thing you can do with these cars is to expect a general purpose mechanic to get things right. You need someone who spends their days working on European cars with a heavy dose of Volvos.

John

Reply to
John Horner

Has he replaced or resoldered the fuel pump relay? That's the usual cause of this problem, the pumps normally last at least 150K and usually longer, I've never heard of a new one being bad.

I agree with the other person who replied, find a Volvo specialist, these are good solid cars and not difficult to work on but they're quite different from the typical domestic or Japanese car, you need someone familiar with European stuff if not Volvos in specific.

Reply to
James Sweet

I concur. In-tank pump failure is likely. Electrical circuit is usually ok, but do check fuses and tachimetric relay as well. If in-tank pump fails or does not deliver enough fuel to main pump, then main pump will _not_ provide enough pressure at fuel pressure regulator at the fuel rail. Pressure spec is about 50 - 65 psig for LH-jetronic injection. Easy to check. Replacing in-tank pump is not difficult. See FCP Groton LLC for parts.

Reply to
jch

Not so sure about the Groton in-tank pumps. I just installed one on our '93 240 and it is very noisy. I don't like that it was an unbranded part in a clear plastic bag without even a country of origin. Come to think of it, I think that US law requires everything to be labeled with country of origin.

John

Reply to
John Horner

I'm pretty good with a soldering iron. Is it easy to find and re-solder the relay?

Reply to
piergud

Yeah it's in the fuse panel, in my '87 that's behind the ash tray under the radio, I'm not sure if a '92 is the same.

Resoldering it is a simple matter of popping the cover off and flowing a bit of fresh solder on the big joints, it'll be obvious when you get in it.

Reply to
James Sweet

Another possibility, that a good Volvo mechanic would be aware of, is the rpm sensor mounted on top of the bell housing. When they go 'blinky', they will cause the problems that you describe.

The ECU has to have a signal from the rpm sensor, before it will turn on the fuel pumps. No signal, no pumps.

Reply to
gs1ignavus

Good point.

Sometimes the sensor is OK, but the connection to the wiring harness gets dirty.

Plug and unplug the connection (near firewall, at end of sensor wire) a few times.

You never know...

Reply to
zencraps

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