Fuel Pressure Regulator NOT the problem.

volvowes79 · Post by **volvowes79** » 22 Apr 2011, 09:04

I am desperate for help.My 2004 v70 started stalling with the engine light on. The autozone code read Fuel pressure regulator. i have seen on other posts that others have had this problem and replacing it did the trick. I am the other side.It didnt fix it, then I started with trying to change the fuel filter. Turns out volvo did not put a serviceable fuel filter on the certain v70's. I couldn't believe it but it is absolutely true. I changed the plugs, took it to volvo and for 90.00 they told me exactly what autozone said- fuel pressure regulator. They said it could be the fuel pump control computer now?? I could really use some advise.
thanks

Post by **VCA** » 22 Apr 2011, 20:20

volvowes79 wrote:I am desperate for help.My 2004 v70 started stalling with the engine light on. The autozone code read Fuel pressure regulator. i have seen on other posts that others have had this problem and replacing it did the trick. I am the other side.It didnt fix it, then I started with trying to change the fuel filter. Turns out volvo did not put a serviceable fuel filter on the certain v70's. I couldn't believe it but it is absolutely true. I changed the plugs, took it to volvo and for 90.00 they told me exactly what autozone said- fuel pressure regulator. They said it could be the fuel pump control computer now?? I could really use some advise.
thanks

So it has a new pressure regulator, but no change in behavior or codes? I'm still wondering if your V70 has a fuel filter. Can you post the first 11 letters of the VIN? [You don't have to give us the chassis code, the last 6 digits, if you don't want to.] It's certainly could be the fuel pump module, but let's start with the easier/cheaper stuff first. Do you have access to a fuel pressure gauge?

Post by **jimmy57** » 22 Apr 2011, 22:03

04's with the steel tank have the filter integral with the pump and sending unit.

volvowes79 · Post by **volvowes79** » 25 Apr 2011, 08:49

i will be with the car this evening and post the vin, but i am 100 percent positive that theres not a serviceable fuel filter, its somehow combined with the fuel pump.; (still not sure whos bright idea this was)
i do have access to a fuel gauge, when i turn the key just to on, the pump was generating like at a 10 and when the car was started it jumped up to almost 60.
its really noticeable when its idling, but this weekend it left my wife and kids in the middle of the road. completely died but when I got there 20 minutes later- it fired right up.
thanks for responding

volvowes79 · Post by **volvowes79** » 26 Apr 2011, 10:28

yv1sw61t042350185 is the vin.

i have no idea where to start. im leaving for texas and this is our only car for my wife. ahhhhhh!

Post by **VCA** » 26 Apr 2011, 11:30

volvowes79 wrote:yv1sw61t042350185 is the vin.

i have no idea where to start. im leaving for texas and this is our only car for my wife. ahhhhhh!

You don't have a fuel filter really, this is a California emissions vehicle (emission code "T") car, and as such, it's a ULEV, so there's no external filter. T here's really only three possibilities: the pump is failing, the PEM (pump electronic module--the electronic part that controls pump voltage and current to regulate pressure) is failing, or the filter's clogged. Given that it runs sometimes and not others, I'm leaning towards pump or PEM failure (the 960 did something similar, and I noticed that when the car died, I couldn't hear the pump running with the key in II, so I changed the fuel pump). The pressure code was recorded because fuel system pressure wasn't what was expected (of course, the pump wasn't running). Pump p/n for your car is 30794757, PEM is 30769225.

Does it ever stall right away when cold, or does it have to be with the engine running for some time? Is it better or worse when it's hot out? How about when it's wet out? When it's running okay (like after a cold start), does it accelerate well?

kiss4afrog · Post by **kiss4afrog** » 29 May 2011, 21:47

Just curious where you are with it. What have you found or what have you tried in the last month?

barbershores · Post by **barbershores** » 19 Jan 2015, 13:36

Picked this up searching around for similar problem on my s40.

http://repairpal.com/hard-start-due-to- ... ulator-053

LuthierIan · Post by **LuthierIan** » 16 Sep 2021, 01:10

I know this is an old thread but it’s still being accessed, so I offer some additional info that has taken me 3 weeks to work out;

there are several different fuel control systems on P2 V70s, XC70s and XC90s dependant on year/month.

the system often discussed has a PEM (or FCU) which controls fuel pump output via a PWM signal from the CEM, this system has a pressure sensor on the end of the rail and a (mechanical) regulator somewhere between the send and return lines, can be in the engine bay by the RHS drivers wheel or actually in the head of the fuel pump! The PEM can be located near the fuel filter, or in the spare Wheel well in the boot or on top of the fuel tank!

However, you may not have a PEM at all. A few models are ‘controlled’ (just switched on really) directly from the CEM (via the fuel pump relay). These pressurise the fuel line, but have no pressure sensor (or even fuel damper in my case), and rely on a mechanical pressure regulator built in to the fuel pump head on the return line in the form of a pressure relief valve.

How can you tell? Apparently from the VIN - but this didn’t help me. The clues are; no pressure sensor on the rail, possibly no fuel pressure damper fitted, no PEM anywhere! The definitive test is to take the pump out and look up into the head, if there is a metal insert with a hole in the middle and a star clip holding it in place, then that’s the regulator on your system.

You will need a replacement pump with one of these built in if the regulator has failed. If you get one without this, it might fire up and idle but will likely falter under load.

To compound the problem, several different wiring configurations exist,
1) with all the connections on the RHS
2) with all the connections on the LHS (where the second fuel sender is located)
3) with a combination of some on each

In searching for your PEM (which you may not have), follow the wires away from the pump, if you have none heading towards the fuel filter area, spare wheel well, or top of the fuel tank, then you probably don’t have a PEM (like me!)

I highly recommend getting the correct tool for removing the pump and/or second sender - at only £20 they will save you breaking the plastic locking rings.

Post by **abscate** » 16 Sep 2021, 04:50

Sorry you had to go around the Wrekin on that one, Lutheran.

Thanks for the informative post.