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

RMReese · Post by **RMReese** » 12 Jan 2017, 13:45

Another note - when we removed the original pump, we did pump fuel out of the RH fuel tank, taking it from the access hole created with the old pump removed. Pumped it to just about empty. After installing new pump, we have poured ~3 gallons back into the tank, via the fuel filler neck.

Does anyone know if the fuel filler would divert fuel over to the LH side of the tank, and then rely on the pre-pump (supply pump, sorry can't recall it's correct name this instant) to get fuel to the RH side?

It does seem we are able to get fuel from tank, since manually (or mouth-ually, more accurately) sucking on this temporary fuel line does yield fuel.

Thanks all, for helping us through this. Going to give FCP a call too, and see if they have any ideas for testing the pump. Doubtful we can return it, since we cut the wiring harness off and did the through-the-floor install.

RMReese · Post by **RMReese** » 12 Jan 2017, 14:17

Just spoke with FCP, he suggested more fuel in tank, that it's possibly a priming issue. Any thoughts on that?

Post by **scot850** » 12 Jan 2017, 14:55

When I re-filled my tank after replacing the fuel pumps I used maybe 1-2 gallons. The fuel tank is designed to transfer the fuel from left to right half. If you somehow reversed the wires it is possible you may have damaged the valve in the ejector (the LH 'pump', it is not actually a pump).
The fuel system is a little complex on these cars, but is you look up the rear sub-frame repair on my 2000 'R', you should see several pictures of how the pipes are routed, which includes the roll over valve, the pressure valve on the line to the LH 'pump' and the pressure tanks to prevent over pressure when temperatures arrive.

Neil.

RMReese · Post by **RMReese** » 12 Jan 2017, 14:56

Another update. Loosened pump w/o disconnecting, but could see that there is plenty of fuel covering assembly, so doubtful it is a submersion/priming issue. <sigh>

RMReese · Post by **RMReese** » 12 Jan 2017, 15:04

Thanks again Neil. I'll look that up. Meanwhile, this ejector - it is somehow electrically linked to the main fuel pump? Or is it powered separately (if it's powered at all...)

It seems that even if it were damaged, we'd get fuel pumping out of the main pump from the RH side of the tank which has gas in it, until it was empty or low. But maybe that's too simple!

Post by **scot850** » 12 Jan 2017, 15:07

Check on page 5 of this thread as it may help you understand the layout of the fuel/emissions system.

https://www.matthewsvolvosite.com/forums ... e&start=40

Neil.

RMReese · Post by **RMReese** » 12 Jan 2017, 16:00

Thanks Neil. Also found a Volvo parts diagram. Still befuddled at the no pumpage from "running" fuel pump. Guess we're going to have to bite the bullet, take it out, and bench test it.

Post by **misha** » 12 Jan 2017, 16:30

Put more fuel in the tank....3 galons is about 10l.
If car is on unleveled surface it could be that fuel doesn't reach fuel pump.

RMReese · Post by **RMReese** » 12 Jan 2017, 16:50

Problem solved - or at least identified. Removed assembly, found pump broken off at stem. Disheartening to say the least! I guess the positive is that it wasn't us this time, or the car! So, she'll sit for a few more days... really too bad this didn't happen in summer when I could hop in the old 245 in the interim...

THANK YOU ALL!!

Dang expensive OEM parts!

Here's the failure:

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

Re: 99 V70-XC New Fuel pump - starting procedure?