Volvo S70 not starting - Hissing sound near fuel filter

HobbesMRH · Post by **HobbesMRH** » 27 Jan 2019, 09:21

A few weeks ago it got really cold here and my Volvo wouldn't start. I had it jump started a couple times, then on another cold day jumping wouldn't start it at all, so I bought a new battery. After that it was still struggling to start, turns over just fine but no start. I tried drying out the spark plugs in case I had flooded the engine, and got it to start with the "lawn mower" method of holding down the gas pedal and cranking the engine for 30 seconds or so. After some more rough starts it now wont start at all. The last time it started I had a gauge hooked up to check fuel pressure it was normal but dropped quickly after shutting the car off.

Today I used a jump wire to keep the fuel pump running and could hear a hissing sound under the car around the fuel filter/regulator. I'm linking a video so you can see/hear whats going on underneath. I assume this is a big vacuum leak, not sure if this is something that would keep the car from starting. It never had any issues once it got going.

Any ideas as to where specifically to look?

[youtube]kBAhcor0PR0[/youtube]

HobbesMRH · Post by **HobbesMRH** » 27 Jan 2019, 10:28

Best guess at the moment is a bad oring in the FRP for the hiss, not sure if that's enough for a no-start.

Post by **misha** » 27 Jan 2019, 16:57

Since the pump was running constantly...i would say that the "hissing" is just the fuel pump sound.

Another guess would be bad fpr which is failed internally,returning all fuel back to the tank all the time.

HobbesMRH · Post by **HobbesMRH** » 28 Jan 2019, 07:12

Thanks for the reply. The sound of the hiss was changing when I put my finger where the FPR connects into that bracket. Sadly I managed to snap one end off the bracket and I can't seem to find that part online. I'm going to see if the junkyard nearby has any S70s and maybe I can grab the whole unit.

Post by **misha** » 28 Jan 2019, 08:00

Late 850 with M4.4 like mine have the same setup.

HobbesMRH · Post by **HobbesMRH** » 30 Jan 2019, 07:08

I was able to find a FPR/connector at a junkyard but it didn't help the car start. Going to try to do a compression test.

Post by **misha** » 30 Jan 2019, 08:50

Why didn't you grabbed a fpr while you were at junkyard?
I would say that it is the problem.
Could also be ECT or it's connections.
Is check engine light on?

Klausc · Post by **Klausc** » 30 Jan 2019, 12:33

If the spark plugs were/are wet, why do you suspect fuel delivery? What about spark? Is the coil OK?

HobbesMRH · Post by **HobbesMRH** » 30 Jan 2019, 12:36

The fuel delivery seems ok, the pressure just drops quickly after shutting off the car. It also sounded like air hissing and it sounded different when I put a finger over where the FPR plugs into that connector so I thought that might be causing the pressure to drop.

There is spark. Going to try the compression test when I get a change and check the timing.

HobbesMRH · Post by **HobbesMRH** » 06 Feb 2019, 06:50

Compression was a bit lower between two cylinders but not something that should keep the car from starting. I tried replacing the fuel pump with one from a junkyard. It was able to get it started after cranking for awhile and I was able to start it again 45 minutes later, but again it wouldn't start this morning. Just cranking. Going to check the fuel pressure again later but I'm not sure what it could be. I can't see any signs of fuel leaking around the injectors Maybe the camshaft sensor?