1997 850R Wagon: Bad Fuel Pump?

PaulM850R-960 · Post by **PaulM850R-960** » 18 Jan 2012, 11:54

My 850R wagon would not start at the airport after returning from a flight at 11pm (argh!) I suspect the fuel pump or relay. Happened once before but eventually started and ran fine for some time. How do I check both of these items, are there 2 fuel pumps with this vehicle and I assume you have to drop the tank to replace if it is the pump. Please advise and thank you in advance for your help.

Paul

Post by **erikv11** » 18 Jan 2012, 13:55

Does the car have pressure at the fuel rail, with the key turned on? If it does, then look elsewhere for the problem e.g. cam position sensor or crank position sensor (check if the wires are getting spark), or ignition parts.

only 1 fuel pump on an R

Fuel pump is accessed through a port under the rear boards, pretty easy, no fuel tank moving required.

Checking the relay: https://www.matthewsvolvosite.com/forums ... =1&t=24929

If the relay is good, does the fuel pump hum? When you turn the key part way, does the fuel pump hum? It should. If not, pump is bad.

If the relay is bad: https://www.matthewsvolvosite.com/forums ... php?t=9681
see also: https://www.matthewsvolvosite.com/forums ... hp?t=32386
if the pump is bad: search the Repair Database for the DIY on fuel pump, not a bad job.

PaulM850R-960 · Post by **PaulM850R-960** » 21 Jan 2012, 18:14

Thank you for the help. Good spark, but no fuel when key is on. Tried the relay trick with the paper clip with no change. Must be the pump. Any other tip welcome, but thanks again

Post by **erikv11** » 21 Jan 2012, 20:15

One last thing: if the pump is bad, then you will not hear it hum when you turn the key to position II (where the dash lights up, but the starter does not crank). Just turn the key and listen carefully. Better yet, kneel on the rear seat passenger side with your head leaned over toward the floor of the cargo bay, and have someone else click the key. If that pump comes on, guaranteed you will hear it hum. If you don't, then it's time to get a new fuel pump.

The Volvo pump is more expensive than the aftermarket ones. I went with the Volvo branded one. A lot of people go with Walbro brand they work fine but are noisier. You only need the insert. If you have the time, first remove and take apart the bad fuel pump, then you will understand exactly what you need and can get it.

D_V_ENT850R · Post by **D_V_ENT850R** » 22 Jan 2012, 05:51

Kick the tank on the right side under the car and crank it! It will start and run for a little bit! Bad pump! That's what I had to do to get mine home. Kicked the tank on the pump side and started up!

Post by **steve850** » 16 Apr 2012, 23:20

I second the tank kicking. A good ( careful) shot ti the bottom right of the gas tank with a rubber mallet will usually unstick a bad pump long enough to get you a few miles. It nay take more than one shot every few blocks. Also, if it is a no start condition that resolves with a kick, it is the pumpvfor sure. Volvo or Bosch if you want it to last

deano1 · Post by **deano1** » 06 Jul 2022, 16:46

"only 1 fuel pump on an R"
Yes, other port is for fuel transfer/balance and fuel gauge sending unit.

"Fuel pump is accessed through a port under the rear boards, pretty easy, no fuel tank moving required."

Nope, pretty sure you can't remove fuel pump without dropping rear sub frame partially at least unless you're cutting holes in the rear seating area I Just did this on 1999 S70 AWD and they are identical layouts.
Cheers

Post by **scot850** » 06 Jul 2022, 19:05

Old thread alert!

850R ( is FWD) only has one pump and even the V70R has only one pump. The AWD V/S70's have a 'saddle' tank that is almost 2 halves lopped over the propshaft. The RHS has the pump just as any FWD. Difference is on an AWD you have to drop at least the front of the tank to access, but often the whole rear sub-frame and fuel tank.

FWD is accessed through the port in the RHS of the trunk area.

Neil.