DIY - Fuel pump on 2004 XC90 is killing me Topic is solved

Joelfixesstuff · Post by **Joelfixesstuff** » 01 Oct 2017, 07:03

Trying to replace the fuel pump in a 2004 Volvo XC90 (2.5, 2WD).

I not an expert mechanic by any means but pretty decent at following directions and whatnot, but can't figure out for the life of me why it doesn't work.

After replacing fuel pump, engine won't catch. It sounds like it's not getting enough fuel, but I hooked a pressure gauge up and verified that there is at least some fuel coming into the fuel rail (just not sure if it's enough).

I'm wondering if there is some trick or adjustment or setting on a new fuel pump that some of you experienced folks might know about that I'm just not aware of.

Here are some pics of what the pressure gauge is showing:

My setup, with pressure gauge attached to fuel rail

Trying to crank engine

Trying to crank the engine and pumping accelerator once

I'm at wits end. I even tried putting the old fuel pump back in to test if it was just a bad pump (the old one wasn't completely busted, just not working right), and it's the exact same problem as the new one.

Also, I audibly verified that while the key is turned on, in the last position before cranking, both the fuel pump and the fuel sending unit are making noise for a couple seconds like they're priming.

Anyway...I know that's a lot but if anyone has any ideas before we shell out cash for a mechanic, I'd appreciate it!

Post by **cn90** » 01 Oct 2017, 08:51

Search forum for "PEM".

viewtopic.php?t=36866&start=14

Joelfixesstuff · Post by **Joelfixesstuff** » 02 Oct 2017, 12:01

Thanks! In looking through this...PEM certainly could be the cause. Some of the symptoms match up. I guess my question is before I buy a new one, is it possible/likely that putting in a new fuel pump would cause the PEM to just completely short out like that?

Post by **precopster** » 02 Oct 2017, 12:10

The return line is easily kinked on both the new and old pump. Check the return line carefully for kinks.

Try to power up the fuel pump independently and check pressures.

Joelfixesstuff · Post by **Joelfixesstuff** » 02 Oct 2017, 12:29

So I'm going to go ahead and display my lack of knowledge here, but what kind of equipment do i need to put power directly into the fuel pump?

Post by **precopster** » 02 Oct 2017, 20:34

Look at the old pump assembly. Identify which 2 wires lead directly to the pump and identify the terminals on that top hat. Remove the connector going to the pump.

Using 2 wires, some alligator test leads and a 12V power source you should be able to power up the pump. Polarity is important however getting it wrong the first time won't break anything because this is independent of car's electrics. In fact disconnect car battery while you do this for peace of mind.

Joelfixesstuff · Post by **Joelfixesstuff** » 05 Oct 2017, 08:55

Just a little update here...

I put a little more fuel in the car so it was closer to halfway full. I primed it about 12 times in a row to make sure there was pressure in the fuel rail. Then it started.

The little bit of fuel pressure I was getting off of the recommended 3-5 primes just wasn't quite enough.

Post by **matthew1** » 05 Oct 2017, 09:55

So it's fixed?

Joelfixesstuff · Post by **Joelfixesstuff** » 10 Oct 2017, 08:21

Yep! All good. Sorry for taking so long to follow up.