Hello again lads.

My '93 850 wouldn't start at the gas station tonight. It's been running just fine.
I tried cranking away and it just wouldn't start. The fuel pump relay is less than a year old, but I pulled it and jumped the front and back pins. No start. I called AAA, and the first thing we tried was spraying ether into the throttle and the engine started briefly several times.

So it looks like a fuel issue. I'm going to spend some time searching the problem here, but if anyone has some thoughts on where to start troubleshooting, it would be very much appreciated.

Thanks!

thumbs

Turn the radio and cabin blower off and tilt the rear seat backs forward. Then jump 15 & 87 of the relay, turn the ignition on, and listen for the fuel pump - it should be running. Turn key off.

Lift the inspection plate and check the wiring at the pump.

Last resort is to run wires to the pump, but you don't want any sparks close to the pump, so make the final connection at the battery.

Klaus
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Did you do your Random Act of Kindness today?

Klaus,

I jumped pins 15 & 87 and had the AAA guy listen under the trunk for the fuel pump noise and he didn't hear anything when I turned on the ignition. I didn't hear anything earlier.

Charging the battery right now. I'll check the wiring at the pump in the morning and let you know.

Is there any way to determine the positive and negative wires at the pump? Does it matter? (if I run a wire from the battery?)

Thanks Klaus.

- thumbs

If I find my wiring diagram, I will let you know. Use a multimeter and check continuity for the ground.
The 15&87 plugs wire directly to the pump. You are looking for breaks in the wire at the pump.

I suspect you will need a new pump. Probably a filter also.

Klaus

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Did you do your Random Act of Kindness today?

Klaus,

You're not online, but this is what I discovered this morning.

No power at the fuel pump connector with my NEW fuel pump relay in. However, there is power when I jumped pins 15 & 87 with my paperclip. What's with that? (Growl)

No sound from the fuel pump when I turn the key on and no start.

Is there any reason for both the relay and the pump to fail simultaneously? Does the fuel pump relay require the fuel pump being plugged in to operate?

And, does checking the fuel pump for resistance provide any useful information? Mine shows no resistance that I can see - just like a complete circuit.

Guess I should start thinking about a replacement.

Thanks for your patience. Will watch for your response.

- thumbs

I'm curious about your testing procedure.

Remember that with the relay in place, it will power the pump for about 2 seconds to prime the line when you turn the key to pos II, but will then cut the power to the pump until you start the engine. (I'm not 100% sure of the specifics of the electrics of it, but I suspect either the key to pos III or input from the CPS or something like that is the signal to power the pump again - regardless, the important part is that the relay cuts the power in pos II).

There are many reasons the fuel system works this way.

If you turn the key to pos II and then walk to the trunk and put your probes on the wires, you will not see any voltage, because the relay will have already turned off.

This may explain why you saw power with the pins jumpered but not with the relay in place.

Another important thing to test is that the power is getting from the outside of the pump assembly to the inside of the pump assembly. My fuel pump died some time ago and the electric pump inside the assembly seems to run fine (though it has ~200k miles and ~12 years on it so I won't be re-installing it!). The real problem was that the wires corroded at the point where they traveled through the pump assembly and the power wasn't getting through to the pump.

If you can get away with only replacing the pump, you'll save a bunch of money over buying the whole assembly.

You can likely get a really good assembly from a junk yard like Strandberg (which is what I did).

There are many places to buy new pumps.
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1998 V70 AWD->FWD->AWD Turbo 220k+

Just finished installing the new fuel pump. Started right up.

There was a small mass of thin black plastic shavings tangled in the bottom of the old pump fixture when I pulled it out. More on the bottom of the tank.

What WAS that stuff?

Turns out my relay was alive and well. Appreciate you taking time to explain how the relay functions.

Thanks for helping out.

- thumbs

jadnhm,

Thanks for chiming in.

Now I'm not so concerned about the relay, a bit of a relief. Getting ready to pull the fuel pump right now.

Is it inadvisable to drive the car with the jumper instead of the relay? I was doing it while the old relay was starting to fail. After the car starts, does the fuel pump run constantly? ...Like my paperclip jumper would have it do?

Thanks again.

- thumbs

Except for emergency use, I would not drive the car jumpered. The wire gets too hot. Yes, the pump is always on with the relay in place and the engine running. What the relay does is prime the fuel pressure and turn the pump off in case of accident - engine stops running.

Klaus
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Did you do your Random Act of Kindness today?

Any year 850, including 1998 S/V70, fuel pump will do. Also grab a relay while you are at it. There are 2 different relays, depending on turbo/NA and manual/auto. Be careful with the plastic connectors, they get brittle with age.

Klaus
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Did you do your Random Act of Kindness today?

Well, the fuel pump is shot. But I don't know why a new relay would go south on me at the same time. Heading out to get a replacement fuel pump. I'll look for the relay as well.

I'll let you know how things go. And thanks again.

- thumbs

Depending on how the pump dies, it could have overloaded a diode in the relay.

Good luck,

Klaus
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Did you do your Random Act of Kindness today?

Here's a picture of the plastic shavings.

Wow, that looks like it came from the inside of the caseing on the fuel pump. You might want to think about fishing out what you can see in the tank.



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Did you do your Random Act of Kindness today?

Yep. I fished out a small handful from the bottom of the tank.

One last question if I might. I have a check engine light now after the fuel pump install. Did I mess something up? Don't now much about a CEL on the 850. Is there a reset or code clearing procedure I should perform?

Thanks again.

- thumbs

You have an OBDI box on the right front fender. Use it to extract the codes and to clear them. The codes will be in A2 and A6 for the engine. Follow the guidelines about a page or so down from here:

http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

Klaus
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Did you do your Random Act of Kindness today?

Klaus,

Just performed the fault code retrieval for A2 and A6.

Got 1-2-1 in A2. Then I tried the code erase procedure, but nothing happened (no lights-??) Did the retrieval again and got my 1-1-1 without erasing.

1-1-1 in A6. Started the engine and no CEL!

Thank you VERY much, Klaus.

- thumbs

A2 1-2-1 is the MAF sensor unplugged. If you didn't unplug it, then with the engine off, clean the electrical contacts to be safe.

I used to go through every OBD port checking for codes, every time I changed the oil. Some codes are stored and 'pending' and should be erased. You can find all of the codes on a list

http://volvospeed.com/vs_forum/topic/47502-dtc-information/

The only code that can never be erased is the B-2 1-2-2, cruise control used under 25mph.

Klaus
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My advice is free, so you got what you paid for...

I'll do the fault code retrieval, and the erase fault codes procedure.

Thanks for sending the link.

- thumbs

Klaus,

Whoopie! Done. Started right up with the new fuel pump.

Found a bunch of thin, gnarly plastic shavings on the bottom of the fuel pump when I pulled it out.

Another small pile on the bottom of the gas tank as well. Did the old unit spew these shaving out when it died?

Anyhow, thanks for steering me through this repair work.

- thumbs

Those plastic shavings are probably part of the impeller.

Time to replace the fuel filter, when it is warm, dry weather.

Klaus
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Did you do your Random Act of Kindness today?

Getting ready to pull the fuel pump right now. jadnhm explained to me why I was not getting power at the connector with the relay installed. It turns off after a couple seconds in position II I understand.

Here goes. Back later.

- thumbs

I'll use my multimeter to determine the ground wire.

Do these fuel pumps just go bad, or can they be "serviced" is some fashion?

Thanks.

- thumbs

Sometimes you get lucky and they overheat and quit for a bit, which is a good warning. Mostly, they get noiser and then just give it up after shut down.

BTW, check fuse #1 and #2(fuel pump and alarm).

Klaus
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Did you do your Random Act of Kindness today?

I had my manual with me, so I checked the #1 and #2 fuses right away. Thanks.

I know there's a few Volvos in my local junk yard. Do you know what years and models have compatible fuel pumps for an inexpensive fix for my '93 850? Gonna have to try getting this fixed tomorrow.

Thanks.

- thumbs