2004 XC70 no start - faulty fuel pump and/or electrical connections? Topic is solved

enotslim · Post by **enotslim** » 28 Jun 2025, 09:31

Yes. More than one year later and the fuel pump has been working fine. I was concerned that I might have failed to secure the driver-side level sensor to it's fitting during reinstallation. Decided it's not worth dissassembling to check and so far no problems.

awizarddresden · Post by **awizarddresden** » 28 Jun 2025, 10:01

You're an absolute life saver. Gonna grab a fuel pump and all the stuff to do one!

Post by **abscate** » 08 Jul 2025, 03:02

Thanks for closing loop on this enotslim. That v70 you donated is still tooling around upstate nY doing social good.

Appreciate it, and the work you do in these troubled times

Post by **DavidE7** » 13 Jul 2025, 20:59

abscate wrote: ↑03 Mar 2023, 03:59 Don’t guess in that plug pins there please. You are applying current to a pump immersed in gasoline.

--end quote --- I deleted the end quote HTML on accident...

Current to the fuel pump doesn't cause any problems as long as you aren't adding oxygen to the inside of the fuel tank...

[Car companies did a lot of testing to validate the safety of fuel pumps inside the fuel tank and some car companies add a flame arrestor to the inside the filler pipe because of the increased flammability of ethanol E85 compared to regular gasoline. The printed ink on the fuel height gauge contact board will short out if fuel pump power is run across it.]

Post by **jonesg** » 13 Jul 2025, 21:36

DavidE7 wrote: ↑13 Jul 2025, 20:59
Current to the fuel pump doesn't cause any problems as long as you aren't adding oxygen to the inside of the fuel tank...

true.
I had a bad habit of running around on 1/4 tank in my 740.
the pump died, I pulled it and the elecs were toasted, brushes melted and burned to a crisp.
I yanked the pump from its housing, made in S,Korea, I bought another from autozone for $55.

awizarddresden · Post by **awizarddresden** » 25 Aug 2025, 10:45

An update on my pump replacement. The replacement went smoothly. Still the same issues though. If I let the car sit for a day, the first start the car will shudder and die. If I immediately try to start again It fires right up and runs smoothly.

At this point I'm not sure what is causing the issues. I know I need to do the pcv still. But I don't think it would cause this. I've cleaned but not replaced the maf. And done a visual and tactile check of all the vacuum lines as well.

How much money and time is work dumping into a 220k mile Volvo that I got for 2 grand? I love this car but I don't know if I'm willing to let it control my life lol

2004 XC70 no start - faulty fuel pump and/or electrical connections? Topic is solved

Re: 2004 XC70 no start - faulty fuel pump and/or electrical connections?