Is this a problem with my fuel pump?

[Aussie_S40]

Hi all,

I think the fuel pump on my car is busted. Do you think I'm right? And what's the easiest way to make sure? Here's what happens:

- Usually (but not always) I have to turn the key for about 5 seconds for the car to start.
- More recently, the car intermittently loses power when I put my foot down. This sometimes happens with just a slight press on the gas but reliably happens when I put my foot down a bit harder.
- Occasionally (but not often) it backfires when I keep my foot down while its losing power.

It's a 2000 S40 2.0 Turbo.

Is it the fuel pump? How can I be sure?

Cheers,
Michael

PS. Thanks to everyone here who's been so helpful already!

[jimmy57]

There is a test port on the fuel manifold. It looks like a tire valve stem. You attach a fuel pressure gauge and monitor the pressure. The best is to use a gauge that has a long enough hose to be able to route hose from under back edge of bonnet and watch gauge when you drive. Fuel pressure should be 45 PSI/300kPa/3Bar while driving and even a bit higher for hard throttle, a bit lower when idling. Fuel filter being clogged could cause a lot of what you list but shouldn't make it crank longer to start.
Your suspicion about pump may be correct. If pump is bad it may fail to ever make correct pressure and fall way below target when you are in the throttle.
Other things can cause this too. There could be a crack in the hose between air cleaner and the turbo inlet making the MAF sensor not read correctly.
Check fuel pressure and go from there.