Position II fuel pressure - 1999 V70XC

bcfischer · Post by **bcfischer** » 11 Aug 2020, 10:07

Greetings:

What should the key Position II fuel pressure be at the rail prior to starting the car?

A couple of weeks ago I put a new fuel pump in. My daughter had noticed that the starter was turning over a long time before the engine started. While I was diagnosing that, the old fuel pump fully died, to where a full 12V right to the pump was only delivering about 10PSI and it would drop off almost immediately when the key was kept in the Position II position.

I changed out the fuel pump and the car began working right away. Yesterday I noticed that it turned over 20+ times before starting. I put my rail fuel pressure gauge on. In key Position II, it reads 15PSI and stays there. When started, the pressure is steady at 55-60PSI and it runs fine.

I intend to send this car to my daughter 5 hours away in college in the UP of Michigan, so I don't want any lingering doubts.

Thanks in advance, take care, and stay safe,

Brian
(1999 late in the year V70XC)

Post by **scot850** » 11 Aug 2020, 10:23

That running pressure is about right. I had the dealer check my 2000 V70R and it was running about 63psi with a new Volvo pump and ejector unit in the fuel tank.

I normally switch the key to Pos II and let the car sit for 34- secs before turning the key. I found sometimes if I was too quick it would not start first time. This way it does.

When did you last check your temp sensor of the engine (called the ECT). There are set values for what this should operate at at set ambient temperatures. The connector is also a known issue for breaking wires and poor connection when they get old. Connector is at the power steering pump.

As to the low fuel pressure that is a strange one and why it would be ok when running.

How old is the battery? Is it holding a good charge?

Neil.

bcfischer · Post by **bcfischer** » 11 Aug 2020, 10:46

Some excellent points, some of which I was thinking about already:

Mine is an AWD, so cutting a hole in the back seat very carefully with a dremel, taking the fuel pump out, reinstalling, filling the tank, finding out it was leaking because the seal had folded over, taking the fuel pump out again and trying to catch call of the fuel, putting the fuel pump back in, then working on the patch panel for the big hole I had to cut above the fuel pump amounted to a long time with the passenger side rear door open. I'm going to charge up the battery and see if it doesn't fix the issue. The battery is pretty new, but it might need a top up.

Leaving the car in Pos II for a few seconds does improve starting.

I changed the ECT last fall. However, for northern Minnesota, it was ungodly warm (90F+) yesterday.

Thanks for the good advice. I will let you know what I find after I charge up the battery.

Take care and stay safe,

Brian

Post by **abscate** » 11 Aug 2020, 18:55

That sounds really low for the key on pressure. It needs to be up at 50 psi

Post by **jimmy57** » 11 Aug 2020, 21:41

the 2 seconds of pump run in engine off pos II will get you 10-20 psi for one key on on lots of cars but usually the correct pressure on the third key on pump run.. That 99 has the fuel pressure regulator in a fitting on fuel line back by tank so fuel press regulator was not new with a new pump assembly. The more important test would be cycling ignition on for 2 sec, off, on for sec, etc 3-4 times to get the 50 ish psi built and then seeing how long that holds. if it immediately drops then there is a problem. If letting it leak down causes long crank with black smoke and usually dead miss for a few beats when it does fire off then a fuel injector leak is high on list. If long crank has no smoke and a little lumpy but no so obviously a dead cylinder until raw gas is cleared then it is fuel leak bank into tank through check valve or fuel pressure reg on the car in question. The check valve is integral to fuel pump and regulator on this one is in fuel line back by tank/fuel filter.

Post by **abscate** » 12 Aug 2020, 03:36

I’ll measure mine this am an document it, too.

There is nothing like the feeling of wrapping aVolvo around your Juniorette to send her to college.

bcfischer · Post by **bcfischer** » 12 Aug 2020, 10:44

Greetings!

Jimmy5:, I will try the key on three time test tonight and prop my gauge up so I can see it though the windshield. When I did key on once last night, i hoped out of the car to see the gauge dropping past 30PSI to settle down in the 15-20PSI range. How conveniently located is the fuel pressure regulator?

Abseate: The daughter I am wrapping in the Volvo is my third of four daughters, so I am also solo dog-paddling a sea of estrogen.

Thanks all,

Brian

Post by **jimmy57** » 12 Aug 2020, 12:08

The fuel filter is just out of sight in photo. This is just ahead of rt rear wheel, below back edge of rt rear door under floor. First photo is what the replacement looks like.

Post by **Eddystone** » 13 Aug 2020, 08:39

Brian,

I have to comment that it is interesting that a young person from Duluth, MInnesota chose to go to college in the Upper Peninsula of Michigan instead of a more exotic location like sunny Iowa! Perhaps she should consider binning the Volvo and commuting via the Great Lakes water route. Might take a bit longer, but having a nice cabin cruiser or something sportier would definitely make her popular on campus.

I have live (for a short time) in the UP and northern Wisconsin.

bcfischer · Post by **bcfischer** » 13 Aug 2020, 09:48

Jimmy57: I tried the key on/off sequence three times last night. The pressure quickly dropped down to 10-15PSI. I then tried again making sure that I was only toggling from the Pos I to Pos II and the same occurred. It didn't start rough, but it was dark and and I couldn't see smoke. I'll try again in the harsh light of day and see what I see.

Thanks for the photo of the regulator. That should be easy enough to get to if I have to. Is the check valve in the regulator, or elsewhere? Also, my 1999 V70XC was made late in the year and some of the systems are best described for the 2000 V70XC (most notably the rear brake calipers which I replaced recently). Do you (or anyone) know if the fuel pressure regulator and/or check valve moved for the 2000 model year?

Eddystone: She originally visited Northern Michigan University (Marquette) with a friend whose dad grew up in the UP because the school had a Sustainability major. She came back and described Marquette as 'just like Duluth' only with no parents.Although she seems to think she needs a car, I really love driving out there to drop her off, pick her up, and visit her. Some day I hope to take the shore route to Marquette that goes through Bayfield, Wisconsin and up onto the Keweenaw Peninsula and through Copper Harbor. It turns the paltry 5 hour drive from Duluth to Marquette to about 18 hours.

One of my Volvo projects, behind keeping it starting, is to add pencil beam driving lights to the front for the sole and express purpose of seeing moose on/by the road with enough time to stop.

I like your cabin cruiser idea, but fear that Gordon Lightfoot might have to write the soundtrack to the trip back for Thanksgiving break.

Take care all and stay safe,

Brian