I did a 200+ mile drive yesterday from Tampa to Tavares, FL, and got fuel on my way back at a BP station. Car ran great until the return trip when it would simply stop when we were at a light, at idle. The first two times, first gear, clutch in and cut out completely with no warning lights or any indication of trouble. The third and fourth were stopped, clutch out, in neutral. My first thought was 'bad gas' but there is no idle issue and no perceived performance problems. The second was fuel pump or fuel pressure and maybe the return hose on the fuel pump that some have posted about repairing, but which I have never explored.

Has anyone experienced this? Any help would be greatly appreciated in diagnosing it. I have not yet checkec codes but don't expect to see any. It's almost as if the ignition was just turned off.

 

so your V8V just shut off? were you trying to engage clutch? did it start right up again? stop and go traffic? overheat or extra hot?

 

I would see it it threw any codes as a first step.

 

If you google it, it seems to be a common issue... happened to me a few times, very scary. I never figured out the culprit but it hasn't happened over 2 years now

Edwin

 

I checked codes on Sunday morning and did not find any errors present. Live data (as far as I could tell) did not have any aberrations that I could see, but I am not overly familiar with what normal parameters are for the fuel rail pressures etc.

I did put a bottle of Sea Foam in the tank to (hopefully) eliminate the possibility of water in the fuel fill up or similar. At that point, there was 1/2 a tank remaining.

The lack of idiot lights, the lack of codes, all seem to indicate something to me that is either unattached to a sensor or is not being read as problematic because the computers think it is supposed to happen, like an ignition switch failure or similar. It was almost like the key was turned off, but pressing the start button fired it all right up again immediately.

 

Same here It happened to me a few times a year or so ago with no real reason, once at a stop light clutch in and the other time clutch in and slowly rolling to a stop light. Like you said it behave as if I stop the car with the switch but didn't, it also restarted right away and it was more than a few months between those two events

 

Did you investigate? What did you find if you did....

I initially had a gut feeling that it was a fuel supply issue, like the filter had debris in it and it settled when there wasn't pressure or something similar. It is so strange on a car that has been so trustworthy.

Edit addition: Conditions were around 82-85F and relatively dry for central Florida, i.e. the humidity was present but not mind blowing uncomfortable. Spiritied, but not hard, driving on mostly straight, sometimes long curve, back roads with minimal altitude changes of +/- 300 feet at most through the entire trip.

EmbdenB -- we passed through Weeki Wachi on our way back from Brookesville to Dunedin and then home to Tampa. No Weeki Wachi Astons sighted.

 

Like you I had a look using my OBD II but couldn't find anything wrong, I didn't think it was fuel but more spark related as it didn't sputter it just stop. I always keep an eye for it to happen again but it didn't in such a long time, others reported similar issue of intermittent stalling but lots were due to flywheel inertia on slowing down to a stop. When I installed a new twin clutch VAP raised the idle RPM to eliminate that issue with twin plate clutch as they are so much smaller and lighter. If you ever find the reason behind the issue please let us know

 

Interesting. I was just reading the thread about that from 2022. I had the car serviced at Orlando in January, but I don't know if they did anything software related. I will email Don and ask, he should know as the service manager and maybe has some insights.

This car only has 35K on the odometer, but it is twenty years old leading me to think it could very well be a degraded hose or similar, like the emissions hose in the fuel tank mentioned previously, and addressed by Rich (Red Pants).

 

So, going through my mental check list of 'stuff that triggers codes/errors vs stuff that doesn't' and balancing 'required for the engine to be on vs off' I think that:
It must not be:
coils, plugs, the fuel pump, or air related (emissions), or battery related. These should all trigger codes.

It could be:
a sensor related to speed (since this has always happened at idle, stopped), a clutch reading (based on prior posts), a fuel pressure issue mimicking a fuel cut off triggered by the ignition or power to the fuel pump/system. A filter issue, though I have yet to find a location or part number or even part for a fuel filter on the 2006 4.3. Or something environmental like vapor lock, but I eliminated this because of the immediate restart of the engine without any hesitation.

I am still leaning toward an ignition switch type failure that the car 'thinks' is an intentional shut off, a loose wire or ground? or a fuel supply issue resulting in the same outcome.

Or software. It could always be software.

 

my initiator thought was also ignition switch, but since yours is a 2006 that discounts the ECU in the dash.

i add a bottle of techron quarterly and never let my tand drop below 1/2 tank, especially here in Florida.

you may want to wander over the Pistonheads UK site. they're are lots of intersting topics and solutions over there

 

Take it for a drive with your scantool and watch the fuel pressures.

 

What is the normal range for fuel pressure and which line items should I be paying attention to specifically?

 

The problem is, it is so intermittent that you would have to have that scan tool connected 24/7 and get lucky to record while it is doing it. I think you have better luck getting a Loto Ticket and win, good luck

 

I agree Handyman, it is, as I explained to my wife on suggesting a dealer service visit what I told her: "they will keep it a week, drive it, and charge for the diagnosis with the reply that all dealer service departments use ''unable to duplicate customer complaint' and give it back to me asking me to bring it in again when it happens, again, and the same thing will happen, again.''

I think, at this point, I am going to see if the Sea Foam remedy works (who knows, its so intermittent), and if not, I think logically it is either an ignition switch issue -- because the car thinks it SHOULD be shutting down normally given all appearances, or a fuel issue and the result is the same so I will probably test the key portion of the ignition assembly, and inspect the fuel pump. The fuel pump appears to have the filter as an integrated component so I suspect the entire assembly has to be replaced. Beyond that...and with no codes....I'm somewhat stumped now.