99 V70-XC New Fuel pump - starting procedure? Topic is solved

RMReese · Post by **RMReese** » 11 Jan 2017, 21:27

Just replaced fuel pump with Volvo OEM part. Previously car was no start, power to fuel pump but would not cycle. Now we have cycling fuel pump, but still no pressure (and big thank you to all for the cut-the-hole-in-the-floor-tip, worked beautifully)

Had drained the tank, added three gallons back in, still no pressure at rail after cycling with key multiple times. Several cranks, a few seconds each, still no pressure.

Wondering if it takes a mighty long crank to start seeing pressure, or if we have another problem? Didn't want to keep cranking if that's the case.

Any tips would be sincerely appreciated, it's 8:30 at night, dark, and about 15 degrees out...

Post by **scot850** » 11 Jan 2017, 23:00

When I replaced the pumps (actually one pump and a pressure fed pump on an AWD for balancing the 2 halves of the tank and fuel gauge), I cycled it a few times on the key and it fired right up.

If you put your hand up onto the pump on the RHS just in front of the rear wheel, and get someone to switch the ignition on you should feel the pump buzz for a few seconds. You may also be able to hear it by putting an ear to an open gas tank filler pipe.

If you are feeling it then you should be getting fuel to the fuel rail. There is a difficult to access 2nd Schraeder valve on the fuel pipe from the fuel filter to the engine just in front of the roll valve up behind the RH rear wheel. It has a cap on it. You may be able to reach it from underneath and see if any pressure is there.

If you are getting no action from the pump, are the connections all correct and pushed fully home?

Neil.

RMReese · Post by **RMReese** » 12 Jan 2017, 11:26

Thank you Scot850. We'll look for that second Schraeder valve.

We do have power to this new fuel pump, and it is cycling (buzzing). Our next step was going to be to disconnect the line that returns fuel to the engine, and connect a fuel hose to that, and see if it will pump fuel into a bucket. Possibly locating that valve you're talking about would save us this step.

I will keep this discussion updated and sincerely appreciate the input! As you can imagine, we were pretty disappointed not to see pressure. We wondered if there could have been water in the fuel that froze in the filter (newish, <1,000 miles on it) or somewhere along the line in these bitter cold temps we're having.

Post by **wizechatmgr** » 12 Jan 2017, 13:08

Also check the 2nd fuse from the top in the smaller fuse panel. I ran my pump out of gas recently and it blew. Got no gas but could have sworn I heard the pump cycle with the key.

RMReese · Post by **RMReese** » 12 Jan 2017, 13:18

Thanks Wizechatmgr, we'll check that fuse again. Looked at it when we did the fuel relay check/jump procedure, but you never know.

We just disconnected fuel line that leads to fuel filter, attached a fuel hose to that outlet, put the other end in a small container of fuel and cycled key, new pump runs (buzzes, vibrates so we're assuming it's running), but no action. Does not pump fuel, does not suck it either (we wondered whether something had gotten reversed).

Sucking on this fuel line does yield fuel, so we don't think a pick up inside the tank was damaged. We were very careful handling the pump in our installation, did not hear anything snap or break, all seemed to fit well.

Blowing into this fuel line gets nowhere, so assuming there's a check valve, which makes sense.

We are a bit befuddled, and loathe the thought of taking that pump out again... did such a clean job of soldering/shrink tubing and routing everything. But, if we must...

Any further suggestions/test procedure suggestions would be appreciated!

Again, this was a new Volvo OEM pump assembly.

It was 0 this morning, now warmed up to a balmy 10F. Makes this all such a pleasure

RMReese · Post by **RMReese** » 12 Jan 2017, 13:19

Additionally, the fuel gauge is registering fuel, so that part's working.

Post by **wizechatmgr** » 12 Jan 2017, 13:23

I know the feeling. When I blew my fuse it was 3F out and I had bought the car a week or two prior. Spent that night stalking this forum gaining knowledge.

When I had the fuse issue jumping past the relay would make the pump run but I still didn't get fuel from the injectors nor could I smell fuel at the tail pipe. It shouldn't be this way I don't think nor can I explain it. Replacing all my fuses with those glo-blow fuses so I don't spend hours tracking something so simple down. Good luck - may it be warmer the next time you head out to the car

Post by **cn90** » 12 Jan 2017, 13:37

This sounds like a reverse polarity issue.
Are you sure you connected the wires properly, i.e., correct polarity?

RMReese · Post by **RMReese** » 12 Jan 2017, 13:39

Wizechatmgr, are you saying that your fuel pump cycled (made sounds but would not pump fuel) with the fuse blown?

RMReese · Post by **RMReese** » 12 Jan 2017, 13:40

cn90 - we just checked that. Reversed polarity, cycled key and pump ran (for the same short burst, but making a higher pitched whine), but still no fuel delivered - this still with line connected to fuel out right at pump.