05 - S80 - Engine stalls and shows P0087

iis4isaac · Post by **iis4isaac** » 09 Apr 2014, 11:10

Hello All,

I've been looking for the troubleshooting steps to figure out what's happening here and I thought someone might know them to help guide me.

I have a 2005 S80 with ~156k miles. On a trip back (luckily at the end of an 800 mile trek) it died several times. Basically the engine kept running but it lost power and I cruised onto the should. I turned the engine off, and back on and it started right up. No CEL indicator or anything. This happened a couple of times. Then finally I get a CEL with P0087 (Low Fuel Rail Pressure). I had my scangauge in the car and each time after that when it would lose power I would see the fuel pressure drop from ~44 to ~2 or even flat zero (while driving at 75mph). So this scenario happened once part way through my trip, then didn't happen again for about 1,400 miles. Then happened 5 or 6 times within 40 miles. Then I drove the car the next day, it happened after about 10 miles, this time taking longer to crank and get fuel pressure again. Then it was fine for the 15 mile return trip.

So my thoughts, it could be a faulty fuel pump but could be a failing relay or even a clogged fuel filter (although I'm least suspecting of this) right? What would be a good way of testing this? Would a failing alternator or a bad battery cause this? I didn't think to set my scangauge to show voltage at the time. One odd note is also that when this would happen if my key was in off position my hazards wouldn't work, but in the on position they did.

Thoughts? Testing process?

Thanks!
Isaac

BradF80 · Post by **BradF80** » 09 Apr 2014, 16:08

If applicable, Have you had the fuel pump recall done yet?

iis4isaac · Post by **iis4isaac** » 10 Apr 2014, 05:40

I called Volvo and they said my car is not one of the recalled cars. Plus it doesn't smell like gas inside the car at all.

matt5112 · Post by **matt5112** » 10 Apr 2014, 08:07

There is also this lovely thing known as the pump control module that is exposed to the element in a rather poorly designed plastic case.

If it is damaged it can cause fuel pressure issues.

iis4isaac · Post by **iis4isaac** » 10 Apr 2014, 09:33

Thanks Matt, is there a good way to test this component? Short of getting my hands on a Computer to plug in?

If the Fuel Pressure Sensor was bad, would it throw the code but still run normally? Or would it cause the computer to try to compensate if it "thinks" the fuel pressure is bad? The only way I've tested fuel pressure so far has been digitally while I was driving via the OBDII port.

thanks again for everyone's help!

Post by **chrism** » 10 Apr 2014, 10:09

I would be inclined to probe the pump power wire wire with my multimeter in various locations (just before the control module, between the control module and pump, etc.) and drive the car each time with the meter in view. See if you can detect/locate an electrical power interruption that coincides with the drop in engine power.

iis4isaac · Post by **iis4isaac** » 10 Apr 2014, 16:02

Sounds like driving the car with a multi meter on the pump will tell me if there's a power to the pump issue. what should I be looking for for range?

Bluevanacd2005 · Post by **Bluevanacd2005** » 10 Apr 2014, 19:04

You would need 13v or so to the pump