98 v70 intermittent fuel delivery (?) problem

[Andrewoakland]

Hi. I recently inherited a 98 v70 (wagon). Mileage 150k. Well maintained and have all service records. Twice in the past 12 months, the car either failed to start or stalled out after short trips of 5 blocks or so.

First time, I turned the engine off and returned to the car after about 15 minutes. When I turned the key, the car shuddered and started briefly then died. When I turned the key after that, if i just quickly hit the starter, I'd get a brief rumble then nothing. If i turned the starter over for more than 2 seconds, i got nothing. I tried it again over the next 2 hours, same result each time. Had to tow it home. About a week later I tried it again, and it worked fine.

Second time, my daughter stayed in car and left it running while I went to a shop for 5 minutes. I came out and when I put the car in drive, it shuttered and died. After it died, same experience as the first time. Quick hit on the starter, brief rumble then nothing. This time, though, I tried it again in an hour and it worked fine.

Other than these two instances, I have driven it at least twice a week with no issues.

Best way I can describe it's like running out of gas when this happens. It has lots of gas, and lots of battery. Since I bought it I had the PCV system overhauled and the fuel filter changed. Didn't help this problem.

I would sure appreciate any advice. thanks, folks.

[Andrewoakland]

By the way, these two incidents were months apart.

[jmartin919]

Fuel pump relay?

[Andrewoakland]

Thanks Jay. I'll check it out. You think a bad relay could be intermittent like this?

[abscate]

Yes, it definitely can be.

[jreed]

The fuel pump relay on my 97 855 did the same thing recently. I jumped it with a bypass wire and verified the jumper prevented the stalling problem. Then I bought a new relay and installed it... has been working fine since then.

[Andrewoakland]

Thanks fellas. Couldn't be an easier or cheaper fix than replacing the fuel pump relay so ill give that a go. Is there any way to check the old one after I swap it out to verify that it is bad? So far the problem has been so intermittent (1 out of 200 or so starts) that bypassing the ld one won't give me much information, Im thinking, since it is likely to work with or without the bypass. I'd sure like to confirm the realy as the problem if possible, so i can trust the vehicle again. Again, really appreciate the insights on this.

[xanthefin]

Thanks fellas. Couldn't be an easier or cheaper fix than replacing the fuel pump relay so ill give that a go. Is there any way to check the old one after I swap it out to verify that it is bad? So far the problem has been so intermittent (1 out of 200 or so starts) that bypassing the ld one won't give me much information, Im thinking, since it is likely to work with or without the bypass. I'd sure like to confirm the realy as the problem if possible, so i can trust the vehicle again. Again, really appreciate the insights on this.

Just open the relay its nothing specially sealed on 850 just clipped.

For me here cold environment it had got very crusty after all the time existing. Re soldering with flux and cleaning and maybe replacing the capacitor it is good as new apart contact surface its slightly dirty but i didnt see it any bad personally. I would say all of them are bad due age at this point and should be checked and maintained.

[abscate]

Stick with the OE relay, about $50. The FAE relay has a poor track record here, like a lot of aftermarket parts

eBay Amazon stoned auto pep boys green/ orange flagged parts URO are to be avoided

[jreed]

Agreed with above about FAE... On the OEM relay, the solder joints crack:

Volvo850FuelPumpRelaySolderJoint Cracks Circled 1.jpg (66.57 KiB) Viewed 760 times

I've seen this on Volvo relays from the 1990's and from the 2010's... we'll see if the one I recently installed holds up.