The 2008 db9
Volante lhd with 18000 miles starts amazingly when cold.
When hot , it start easily when within 1-2-3 minutes of shut off.
But if I leave the car sitting 5-10-15 minutes, the attempt to restart fails. Only the second attempt works and it starts.
Sometimes it throws a fuel and emission dash lights with limp mode. Upon restart , limp disappears. The check engine light stays on until deleted.
It does this every day after decent rides.
Many owners have replaced the Bosch fuel rail pressure sensors. I replaced both yesterday. But the issue remains.

I noted the codes today.

On bank 2.
P0087 fuel rail
Pressure too low.
P0191 fuel rail pressure sensor circuit range performance problem.

Sounds like a fuel pump replacement?
Accessible from underneath the Cabrio roof when opened or through the rear seats ? Or through the trunk ?

Any advice would be appreciated

Thank you in advance.

 

What OBD scan tool are you using? You should look at the fuel pressure on both ECUs. Key on engine off the pumps will prime and pressure should maintain. If it drops off quickly then you're looking at pumps. The left bank of the engine is fueled by the right pump and vice versa.

 

Check valves fail. There is a replacement kit for just the lines (in-tank) that have check valves as part of the hoses. Easier than pump replacement and definitely less costly. Unless the parts can't be sourced anymore.

 

Pumps are available for the 2008 and newer cars. While expensive, they're not that much more so than the similar pumps from a Jaguar of the same vintage. I haven't seen the check valves available separately anywhere. If one wanted a cheap fix, they could probably buy a cheap chinese pump from a 2010-15 xk or 2010-2012 xf to harvest the blue bypass valve to repair the pump. Toss the pump motor in the trash. I'd trust the original motor over the cheap-o one.

 

I have a few high end scanners. Maxxis , snap on. Etc I didn’t locate the fuel rail pressure in n the live data

 

begs the question as to why when cold sitting overnight, 100% start with zero failure ever.
and when hot , after 10 minutes , only starts on second try

 

Not sure what it would cost with import fees and such. Might be able to order from a local dealer.

 

this is the check valve people
are referring to ? You know the part number ?

 

On my DB9 Volante I started having hot start issues. Bad check valves were confirmed using my Foxwell 520 and reading the fuel pressure in the live data. Should hold at 40+ PSI, mine was falling off to about 5. I replaced mine by harvesting the check valves from a "cheap chinese knockoff" for a Jaguar XK8. That solved my crummy starting when it was cold. Had I realized what the hoses were shown above I'd probably have gone that route, or just installed the check valves I got at the local speed shop...

My hot start challenging was a ******* starter motor. That ended up being a corroded / loose connector on the positive lead from the battery to the start motor. It was the connector at the disconnect near the battery.

Glad I have a volante - I can get in and out of the fuel tank in about 20 minutes. Actual work with the coupe!

 

please tell me how you access the pumps. I also have the volante.
do the rear seats have to come out ?

 

Part of the job of those valves is to maintain pressure in the fuel rail to prevent vapor lock. If they leak the heat from the engine can vaporize the fuel and push it back into the tank. I was having similar symptoms when mine were going bad. It would crank and immediately shut down. I eventually learned that if I cycled the key on/off/on in quick succession that it would build enough pressure to start.

AM4884 is right to mention the starter battery supply issue. There are a few different reasons for a hot fail to start. 12V supply and grounds are a lot easier to get to than the fuel pumps. Fuel is pretty easy to diagnose once you have an OBD tool that can read and pull codes from *both* ECUs. Otherwise most tools may only see the primary ECU on the right side of the engine. The Foxwell NT530 and a few others have an Aston Martin specific program that works pretty well for basic stuff like that.

Also... I'm not sure what to make of those fuel lines reference at AstonStore. The red connector is meant to attach to the fuel filter of the 2007 and earlier cars and the only right angle quick disconnect in the tank is at the bulkhead fitting to exit the tank. That and the hose length say to me that it's not meant for 2008 and later cars. Not to say you couldn't just remove the pressure valve from the lines and use them to rebuild them on the later setup. If those *are* meant for =<2007 I wonder what you're meant to do with a leaking pressure valve directly attached to the pump cannister. Perhaps the two small screws are meant to jam the original valve closed? strange.

 

on a 2008 volante , how do I access the fuel
pumps ?
rear seats removed etc. Or is there another way?

 

There is a VIN range for these hose kits.
A/B 09174 to A/B 10560 kits used to be about $300.

.

 

Check out this post: https://www.6speedonline.com/forums/...ml#post4949416

And if you search for recent posts by me, there is a thread on replacing pumps/check valves, etc, etc.

Basically you initiate a top change and the volante cover opens up. You shut the engine off when it as maximum open and quickly jump out and put two small C-clamps at the bottom of each hinge to hold it open. You'll need to prop the soft top up as well. The black circular cover is glued in, but comes off easily. At that point it's a standard fuel tank lid. I have a decent hand syphon pump from the auto parts store and it will suck all the fuel out pretty quickly. Careful folks undo the battery before getting into the tank...

Fuel link connectors, one ear clamps, fuel line clamps and in-tank fuel hose are all readily available online. I can't speak to the other years, but you can see my tank guts by looking at my old posts.

Good luck!

 

and this thread has pictures from inside the tank: https://www.6speedonline.com/forums/...uel-pumps.html