2003 s80 Fuel system nightmare - No fuel pressure

lemonlover · Post by **lemonlover** » 10 Nov 2010, 17:28

2003 S80 Non-turbo 2.9L Gasoline 80k miles, sold in the Midwest USA.

Symptom: The car starts, intermittently. Often refuses to start in inconvenient places, but even more often in the garage at home. Currently won't start at all.

I changed the fuel filter. I triple checked that I put it on in the right flow direction.

I then changed the fuel pump impeller segment. That "fixed" it for a few weeks, during which the car ran great. It did decline a little in performance before completely failing again however, subjectively speaking.

I've verified on the bench that the fuel pump relay is making good contact and working 100% properly at 12v.

The fuel rail relief valve (on the rail, under the hood) does not appear to have any pressure on it at all, just a faint whiff of gas when I "depressurize" it. No obvious fuel pump sound on startup either.

The OBDC reports no codes present.

I've verified the 15A fuel pump fuse is OK countless times.

Could my fuel pump have crapped out after only one week on the job? By the way, I tested the old impeller which I removed on the bench too and it spins up nicely at 12v. So it probably wasn't bad in the first place?

What else is there?

Thanks in advance if you can help me further troubleshoot this.

Post by **boosted5cyl** » 11 Nov 2010, 09:11

Ive never actually had to troubleshoot a fuel supply issue before (I might get to in a couple of weeks however), but heres my 2c: It might be time to either borrow a fuel pressure gauge from autozone\oreillys or buy one from harbour freight methinks.

That said, are you sure its a fuel supply issue thats causing the starting problems? Does the tacho jump around at all when you start from cold? It should stay steady around 300RPM when you crank it. If the crank sensor isnt giving a signal, I beleive it cuts fuel, so if you dont see the tacho move when cranking the problem could be that. Sometimes the routing of the crank sensor cabling is affected buy the induction on the starter. In this case, the tacho jumps around like its on crack when you crank the engine over. Mine does this and it seems to get worse when the weather is colder. Im going to insulate mine in aluminum foil.

Maybe a new pressure regulator is needed ($45ish) or the injector rail has a blockage somewhere? I think getting a pressure gauge on there and working back in the system might point to where the issue lies.

lemonlover · Post by **lemonlover** » 11 Nov 2010, 09:46

Thanks for giving me a few new things to consider.

The tach does read 300rpm when cranking.

Since there's no fuel pressure at all at the rail's relief valve, and doesn't sound like the pump is running, I guess this is an electrical problem?

Does anyone have a wiring diagram of the fuel delivery system?

lemonlover · Post by **lemonlover** » 11 Nov 2010, 10:45

Further testing (applying 12v to the impeller from the header) indicated that the pump itself is apparently shot, already.

Any thoughts on what could kill a new Bosch fuel pump in about a week's time?

Post by **boosted5cyl** » 11 Nov 2010, 12:39

I have no idea what might cause it.. Maybe there is a specific installation process? Couldnt find a wiring diagram anywhere, all I could find was the EMS specifications. Theres some useful info in there though.

lemonlover · Post by **lemonlover** » 11 Nov 2010, 20:14

I'll keep that document handy, it does look like it may be useful someday. Thanks!

__CJ__1 · Post by **__CJ__1** » 18 Nov 2010, 01:28

Hi There
Just want to ask if you went to the dealer and replaced the fuel pump?There's a recall on them.Replaced mine for free..no problems.I hope that's the problem not something else.Good luck..hope this helps !!

2003 s80 2.9 none/turbo with 61000 on it.

lemonlover · Post by **lemonlover** » 18 Nov 2010, 09:16

I did take it to the dealer (after it magically started running again) but they claim that it is not under recall, despite it being the pump pictured on page 14 of the service document (attached).

Is it possible that there are some of these pumps with the white flange and wiring harness that are NOT under recall in this timeframe?

They have however found a warranty extension on the vehicle for the fuel pump, but as goes my luck, it hasn't failed on them since I got it to the dealer, and they won't change it until it does fail.