I am a new owner (7 months) of a 1998 S70. My son took the car back to Utah for school and everything ran great. In April he came back home and said the car would occasionally stall out but he would restart it and everything would be ok. Over the past 4 weeks the stalling became more frequent. Not only would it stall at a stop but traveling down the highway it would lose power and sometimes die completely while other times it would "re-engage" as we called it. Meaning the RPMs would go back up and everything would work. In searching the internet the most common cause seemed to be the maf sensor. I removed it and cleaned it as directed and reinstalled it and for about 2-3 days it did not stall. Once the stalling began again I looked on the internet and found that the fuel filter might be the problem. The car has 165,000 and in looking at the filter it had never been replaced. I replaced the filter and took it around the block twice. It seemed to run great. I forgot to mention that when idling it seem rough but not too bad. After taking it around the block I realized that it was idling rough because now it was smooth and had more get up and go power. I parked the car in the drive way thinking all was ok. Later that night (3 hours later) my son took the car to the store 2 miles away and it started to stall again. Only this time after pulling over to start it again, it did not start right away. He finally made it home after stalling it 20-30 times. I then went out to start it only to find it would not keep running long enough to move the car. If I wait 30 minutes I can start the car right up but it runs for 10-15 seconds and then dies. It sounds (seems) like it just does not have fuel to continue running. If I try to immediately restart the car it will not fire up at all. I wait 30 minutes and it does the same thing. During one of the down time I again looked on the internet and found how to test the fuel pump. I got back to the pump and during the initial start up it sounds like it is engaging and working. I am not a mechanic and do not want to take the pump out if I don't have to. I checked the fuse to the pump and it is ok. I am not finding anything else to try other than take it to a mechanic. Since it won't run, kind of hard to do without paying for towing. The parts store employee told me to disconnect maf and see if it runs, when I did nothing changed to what it already was doing in stalling after 10-15 seconds. I was wondering if I might have done something wrong with installing the fuel filter. (double checked to make sure fuel flow arrow is pointing the right direction) Does anyone have any suggestions. Thank you very much for your help.

 

Classic symptoms of either fuel pump or fuel pump relay dying. Do a search on this site; lots of posts with very same problem. That's about the right mileage for the fuel pump to die too.

Here's one; see post #3.
https://volvoforums.com/forum/volvo-...el-pump-53916/

 

To see if it's the relay, remove the relay and connect the switched terminals of the relay together. Start the car, and see if it stays running. if it stays running, the relay is bad. if it quits running, see if the fuel pump is still working. If not, you need a pump. If yes, locate a fuel pressure gauge and check pressure from the schrader valve on the end of the fuel rail- a $25 auto parts store gauge will work fine for this.

 

Which are the "SWITCHED TERMINALS" of the relay? My sedan is in the early stages of this sanario. When checking the pressure, what is the pressure suppose to be? I would also like to know if it's worth getting a used pump (one from a junk yard), and what pumps are best to purchase to replace the bad one.

 

I was looking at FCP & iPd and those sites scare me a little when it comes to purchasing fuel pumps. Sounds like the way to go it to simply purchase an entire assembly but they make is sound like my car has 2 insert options and I need to take the tank/pump apart to see if I can even get a new pump insert to replace my bad pump (assuming that my pump is bad). Who has experience with this situation? Can I take an assembly out of any 850/S-V70 pre 2000 and toss it into my T-5R?

 

RSPI: ck out this thread about my experience with replacing the fuel pump; esp. post #6. As it says in my post, you need to pull the old one and measure the pump's diameter.
https://volvoforums.com/forum/volvo-...uestion-45272/

I would not put a junkyard fuel pump in my car but that's me; figure it's been sitting for a long time and probably rusty.

Everybody who sells them (including ipd) trys to scare you into buying the whole assembly which is very expensive but if your existing plastic carrier isn't cracked or broken you can carefully take it apart, replace just the pump, and re-use the carrier. I would go with OEM Bosch pump.

Fuel pressure should be 43 psi at idle; dip a bit when you blip the throttle. Relay pins to jumper (to bypass the relay) are pins 1 & 3.

 

Thanks. When it shuttered yesterday I coasted back home, swapped the relay with my other car, and it started running right again. Swapped the relays back and it's still running. Took it around the block and it's till fine. These things really suck. I guess I need to check pressure. Maybe it will be low. I need some parts off of a V70 or 850 wagon. I was thinking about taking the pump from there. I'm going to look at a V70 tomorrow. There was a 850 wagon up the road about 15 miles but it has fallen off of craigs list.