Hi all, been following a similar issue on another thread with great interest as I have a similar problem but different, so thought I'd try starting my own thread. Car is an 08 DB9 update model. Driving along, car suddenly goes into limp mode with "check fuel system" previous owner had both fuel pumps replaced to try to rectify, which obviously it didn't. This happened to me twice at about 2 month intervals (its not a daily driver) both times I pulled over, turned the car off and re started and all good. It has never had lumpy idle and runs like a dream (except in limp mode of course). 2 weeks ago it did same again except it added check emission system, tried to pull over, stop and restart, no good, stayed in limp mode, fortunately I was only 5 minutes from home, also this time after I got home there was a stink of cat converter. Spoke to my mechanic (AM trained and 10 years on AM) said to try car next day and report back. Started car, and apart from the check emission message, no issue. The reason I am interested in the other thread on O2 sensor, is that my mechanic mentioned the crack in the fuel tank scavenge pipe (this ended up being the other chap's issue) when I told him it does not seem to happen when the fuel tank is less than half full. He doesn't have an AM code reader but his Snap On code reader came up with : 2106 throttle actuator and 2195/2197 O2 sensor signal bias/stuck lean.
Any thoughts or help greatly appreciated as apart from the pipe in the fuel tank possibility, my mechanic is scratching his head a bit
​​​​​​​Cheers Dean

 

​​​​​​​Just trying to get some help on this. Cheers

 

10 years exp. and he's scratching his head? Which side of the engine is faulting the Oxygen Sensor, start there with fuel pressure when driving. Buy yourself a scan tool and do some investigation on fuel pressures when it happens.

 

Thanks for the reply JDouble, in fairness to him I've read at least one similar issue on this forum that am AM dealer couldn't sort, also he has offered to take the car to his old dealer for me and get the codes from the AM scanner, he only has a generic scanner. But to answer your question, both sides of the engine.

 

Dean, as I understand the throttle actuator can be a red herring code sometimes, and unfortunately your O2 sensor stuck lean code can mean many different things, as well. When I had a similar issue and was misfiring, I believe mine were stuck rich. As J DoubleU suggested, a scanner is a very important tool for you to know if you're misfiring which seems to often be the case when our cars go into limp mode. If you can find out if you're misfiring, you can start to narrow the causes from there.

 

Thanks Astoncarma, I think my next move is to get codes read at AM dealer. Also to see if the fuel tank level has any influence which I suspect

 

I wasn't trying to discredit anyone, but most of the time answers or possibly a fix is mentioned. The response is, I already put a new battery in, or the engine was just replaced. We need specific codes and certain information to help. Otherwise we are guessing, and ****ty guesses come about. Most scanners do not read the module as 2, just one so its really important for which side. Both sides with the exact codes, you best buy a lottery ticket. Fuel system fault message is just that, it's not going to be an oxygen sensor or ignition coil. #1 fuel pressure makes the most sense. If pumps were changed recently were they the correct part? New parts can fail too. They can run hot and slow down the volume or flow. Usually a pump works or dosen't. It's not a unique Aston thing, its design is like any other on the road and could be anything. Make a chart, fuel level in tank, temp outside, how long the car ran for what codes. And you may find a pattern to look closer.

 

All good Jdub, I do see what you're saying and do appreciate the feedback. Astons are good at a lot of things, unfortunately one of those things seems to be curve ***** ​​​​​​
I'll keep you posted on how this goes

 

J DoubleU always gives really good advice here, from what I've experienced. You may want to also follow the thread at https://www.6speedonline.com/forums/...ml#post4842468 which COULD be related to your issue, as well. But like J said, if I had a problem like this, my first try for a fix would always be the battery (if it's older than a few years old), as our cars are so quirky with bad batteries. It's a ~$120 sunk cost that will end up helping you to eliminate at least one avenue and you'll have a new battery at the end of it. Note that our batteries are not easy to get to compared to other cars, so you'll have to be comfortable with hand tools to swap them out. Just offering for consideration to try that, as I went down the long road with misfires on my vehicle and sunk some real cash before the problem was found. You'll find quite a few examples of cars with all kinds of codes being fixed by a simple battery swap, so cost against potential reward, to me it's worth a shot if your battery is old.

Also if you get a new battery, I recommend an AGM battery, as these are safer for cabin-installed applications. Note that you'll need a special battery tender designed for AGM batteries if you do this, which could add to the cost.

 

So have driven it 3 times since the check emissions check fuel issue and its running like a Swiss watch, I haven't filled the fuel tank past half full and its increasingly looking like the scavenge (I think what it's called) pipe insidethe fuel tank might be cracked and letting fuel into the cannister, this is one thing my mechanic said "could" be the issue so fingers crossed.(it's not uncommon apparently) Although I'm not sure if fingers crossed is the right term as apart from the price and availability of parts, the amount of labour required is probably going to make it an expensive fix

 

Update ​​​​​​
Just went for a short drive (this is not my DD) and on the way home it went into limp mode "check fuel system" etc. Pulled over, stopped, took key out, put key back in start it and all clear. Fuel level is below half so there (possibly) goes that theory.
It's doing my head in

 

look up thread started by me
I had exactly same issue and solution is there too

it was bad fuel pump. Replace both , where to buy them is also listed in my post. I had to send my car to delaer first one just said everything is fine. Second one said pump is bad.


if pump is failing it may work intermittently plus car has too pumps to it works but goes in limp mode intermittently.

when I tested the pump outside the car it over heated the electrical wire so much that I am surprise car did not catch fire but I guess when it starts Over heating it goes in limp mode.

please don’t drive the car it gets scary HOT and it’s submerged in the fuel

here is my post

https://www.6speedonline.com/forums/...igure-out.html

 

Thanks very much Wildcat, I have been following your thread and whilst our problems are similar they are also different. I have 2 new fuel pumps in my car and whilst there is always the chance one is faulty, its been throwing different codes to yours too.
I never have starting issues and apart from when it's in limp mode, it runs like a dream. My limited mechanical knowledge tells me if it was a pump getting hot it probably wouldn't be solved by stopping and immediately restarting, which always fixes the issue.
My mechanic has suggested it could be worth replacing the fuel pump drivers which is looking like the next step.
Thanks again for the reply

 

Hmm that’s wired if you have new fuel pumps then it could be the module. I had exactly same symptoms. Car goes in limp mode then I had to pull over, turn off the car and restart it and it will work fine until it goes in limp mode again.
I

 

Cheers bud ​​​​​​
I'll keep you posted