850 Stalling, with a twist...

[Cyman]

My fuel pump recently died, and here's how I diagnosed it:

checked to see if the relay was clicking; it was.

did the paper clip test just to make sure.

took of the fuel pump cover to make 100% sure the fuel pump wasn't coming on.

checked fuel pressure (didn't need a gauge) by turning the key on briefly then unscrewing the cap off the small nozzle to the right side of the fuel rail and pushing the pin. I made sure to have a rag underneath it just in case there was fuel pressure. only one drop of fuel oozed out of the end of the nozzle, so I was sure there was no fuel pressure.

and the final thing I did was unplug the fuel pump and use a multi-meter to make sure it was getting power.

I hate buying parts that don't need replacing, so I did every test I could think of to make sure the pump was the actual problem. Once you take off the cover in your trunk it is a lot easier to tell if the fuel pump is turning on.

if it turns out that the fuel pump is bad, don't forget to replace the gasket at the top of the fuel pump assembly when you do the job. I left my old one in because it still looked fine, but later found that every time I fill my tank it leaks gas all over the place.

[Larmor]

It's on the passenger side, looks like it would be attaching to the car in the direction of the fuel door, maybe (?), and nothing seems to happen when I move it, but what the heck is it?

Manual unlock for the fuel door. If it doesn't electrically unlock like it should (mine certainly gets iffy in cold weather), tug that loop towards the taillights.

[RegisWhite]

Thanks for solving one of my mysteries, Larmor! The funny thing is that my fuel door doesn't have an unlock-from-inside-the-car lever; you just open the fuel door manually. Maybe Volvo was anticipating putting an upgrade in the next year's model, and went ahead and put the part in..? Alas, we'll probably never know. Point is, it's good to know that's not some other weird thing to give my grief later on.

I appreciate all the good tips; I finally got to do the paper clip/jumper thing, and there was no response.

One question for Cyman, if you're still there: What pins/connector(s) did you test with a multimeter to make sure the pump was getting power? I guess I HAVE to assume it's not the relay, since the paper clip test did nothing; I'd sure like to find out about the power issue before I spend money on a new pump, but there are just TONS of wires and connectors back there, you know?

Barring that, I'll have to start looking around for a fuel pump assembly, I suppose...

Thanks...

[anmartin44]

your fuel door locks and unlocks when you lock or ulock your doors. there's a vacuum lock on it. try opening it with your doors locked..

[RegisWhite]

OK, I surrender; it must be the fuel pump! I FOUND the leads to test if the pump was getting power, and, sure enough, it was. So it's time to go shopping!

There isn't much around where I live in the way of salvage yards to explore, so I'll probably have to just bite the bullet and buy one; maybe that's better anyway. For those who have had to do this before, I'm curious as to if anyone has gone any "lower" than a Walbro. There are some floating around out there, new ones, going for about $65, which is about $30 cheaper than the Walbro, BUT... are they any good?

I got my old pump ready to dis-install, except I have to buy an oil filter wrench to help me get that plastic nut off the top.

One other question: with the pump kits, why do they all seem to include what looks like a small length of rubber tubing, and hose clamps? Are they assuming that you'll break something off when taking out the old one, so they want to be ready with a fix, or are aftermarket pumps equipped with a connector that won't "take" the Volvo's snap-on connectors?

Now that I have to do the buying, I want to be super sure I get the right thing, is all.

Thanks for the help! Happy Thanksgiving...

RW

[Cyman]

When I bought my Fuel pump I simply made sure to buy one that looked like the pump that I pulled out of my car. I saw a lot of other (cheaper) pumps that looked as if they were meant for a variety of other car models, not made for these cars specifically. I may be wrong and they could work just fine, I just didn't want to deal with a faulty/strange fuel pump that didn't fit right and I just wanted to get the job done correctly the first time. I ended up getting a bosch for $150 or so. I saw some on Ebay that were cheaper, but I needed the pump in a hurry and a local shop had one in stock.

the pump I got didn't come with a replacement length of hose, but I was able to reuse the OEM hose. it also required that I crimp on different electrical connectors that mounted inside a plug that attached to the new pump. all in all it took about 35 minutes to retrofit/reinstall.

Good luck with the fix!

[RegisWhite]

Howdy, Cyman;

Thanks for the advice and good wishes. I broke down and ordered the real Walbro, since I've heard nothing but good comments about those ones on this (and other) forums and websites. I was able to find a place that had it about $15 cheaper than I'd seen other places. It was "fuel-pumps.net"--not endorsing, just stating that this was the least expensive place for a Walbro that I'd been able to find.

It's supposed to be delivered tomorrow--now that the temperature in PA is going down-down-down, and there's been a cold, steady rain all day long, due to continue! If only I'd been able to get the tow truck driver drop the 850 off right INSIDE of the garage, instead of right OUTSIDE when it broke down! But most of the re-assembly work can be done under cover; just crawling inside to actually install it will be a bit chilly, but if it works in the end, I won't care a bit.

Any precautions or preparations I need to take after it's installed, since you recently did one? Anybody? Anything I need to do to, say, get air out of the line, or anything like that? I'm hoping it's as simple as installing the pump guts, snapping the housing back together, shoving the whole thing back into the cavity in the tank, and then off I go! I'm HOPING, that is...

Thanks to all...