For the mechanically minded. HELP BEFORE I BURN IT DOWN!

[-ToM-]

ok, so to give you a history...

In the last year i have had the car stall and die on a few times...

Once while cruising at 60km/h - started straight away.
Once after driving back from Ardrossan, stopped at lights Started after 30m
Once while cruising at 60km/h - started straight away
Once while stopped at lights. Started after 5m

The last 2 has happened in the last week.

Basically it just happens. No warning. Just stops, warning lights come on.
When it wont start again, it just cranks and constantly turns over like its on the verge of starting.

Also the last couple of weeks ive noticed the revs dropping low when the car shifts into gear while accelerating, almost like its labouring.

The car is serviced every 10,000kms or few months, whatevers sooner.

In the last year ive had ive had:

Throttle body cleaned.
New Top Gun Max 300 leads.
New bosch copper plugs.
Crank angle sensor replaced.
Tensioner assembly replaced.
Transmissions serviced and cleaned.
Regular services.

IE a lot of money, with no real resolution.

Now next week it goes back into the mechanics for a service, and they are going to recheck the CAS which is under a 12 month/20,000km warranty.

Basically im after a second opinion on what could be causing the problem. Basically the only problem i can see is a brown sludge on top of the radiator cap which most commodores around my age seem to accumulate anyway.

Cheers guys

[CalaisJohn]

do you have an over-ride keyswitch in ur glovebox for any factory security/alarm?

[-ToM-]

No, but theres one in my door jamb. Usually its turned on. What are you thinking?

[CalaisJohn]

I had the same symptoms as you described and it turned out being the keyswitch.

check my post here ToM

VN - VP Faults

hope it helps ..

[-ToM-]

might turn it off seeing as i have the alarm and immobiliser installed

[CalaisJohn]

with your car running.. stick ur key in this keyswitch and without turning it just give it a few wiggles and see if you car dies..

[-ToM-]

gave it a go mate, no dice.

[CalaisJohn]

elimination, well that one down. sounds like an intermittent fault you have there good luck in tracking it down

[-ToM-]

My list so far is as follows...

crank angle sensor
Fuel Pump, fuel filter partialy blocked
Coil Packs
Dodgy Relay in electrical system
Key + Ignition Barrel
injector pulse
Faulty Knock sensor
bad earth wire

Im gonna be broke...

[hako]

Try checking for codes as that may give you a clue. How is the DFI module?

[-ToM-]

The last time it was in my mechanic said it didnt spit any fault codes except for the CAS (this was the time after the ardrossan trip)

Im not real good when it comes to engine work, i can only get by on doing basic service stuff

[delcowizzid]

you can take the knock sensor off the list it wont stop it running if it has issues.im in agreance with the security key in the door jam they suck for doing this exact thing .if not that ide be thinking a cheap CAS was put on and its died allready or dfi module under the coils

[greenacc]

I'm with hako and delco, BIG chance its the DFI in my opinion. They normally log codes any or all of 46,47,48,49. Its very easy to replace but expensive to buy. May be worth trying one from a wrecker..

[Nobody Actually]

try the filter champ, same problem, that worked for me, the large one near the fuel tank.

[ausrs]

also check the connection to the bcm and ecm
had a car do that to me a few months ago ended up on a tow truck to get it home ,went through and che3cked everything ,still no good ,pulled ecm and bcm re plugged them back in 6 months later NO issues whatsoever !
cant hirt to try and best part is it is free

[-ToM-]

Thats also an idea, dont think it was happening before i put both my amp wiring in for the sub, and also my greenfoam tune. May give them a check over

[-ToM-]

Dropped in after work.

Cars been serviced, fuel filter replaced, throttlebody cleaned.

Car was scanned for errors - none came up, not even the CAS.

Mechanic said he was going to check out the fuel mixtures and check for irregularities this afternoon.

Its staying at the shop overnight, and tomorrow they are going to check all other sensors for irregularities and go over wiring.

They left it idling for a while today, and drove it around. Reckon's they couldnt get it to stall.

[-ToM-]

Some news.

Fuel diagnostics came up showing it was running very lean. Not sure of the exact wording, but the oxygen sensor came up showing 0.2V which is apparently almost dead, and cycling once every 5 seconds, or once instead of 5 times every second (cant remember exactly).

They are going to replace the oxygen sensor and hopfully it fixes the surging and stalling problem, which sounds like it was due to a lean fuel supply

[50LTRv8]

It is funny that the sensor was not throwing a code?

[delcowizzid]

they dont really set off codes till the final death sometimes by the time they spit codes they are well out of range average life 60000km

[-ToM-]

So far the immediate difference is a healthier idle (was running too rich previously) and slowing down + gear changes arent surging anymore (previously on a lean flat spot just above idle)

Time will tell if my problem has actually been fixed

[-ToM-]

Well, the issue is STILL unresolved.

Some things that have been suggested are:
-thermostat (temp shows around 1/4 most of the time)
-Fuel vaporization in the fuel lines
-Random fuel pump cutouts
-Hot ECU

one observation made today was that when started up, the car puffed a bit of black smoke on ignition, which could possibly be excess fuel? im not getting any error codes.

[strgas]

checked the fuel pressure reg for leaking fuel ???

[VSPantha]

Recently my sister had a similar problem with her VN Exec. Driving along and without warning it would just die... nice when it happens on a busy roundabout! Funny thing is it would only happen when the tank got to and below the half mark. No problems when it was full and would start again after 10 seconds or so. Anyways... get your fuel tank checked. Hers had corrosion and crap in it apparently and was clogging up the fuel intake from the tank... was fixed by replacing the tank. Hope this helps

[Brett_jjj]

mate Id swap the crank angle sensor for a new one,a genuine one.Aftermarket ones are sometimes just as bad as the one you replace.I see you have already replaced this,was it a genuine one?My mate
had trouble with his,replaced it,same trouble,he took it to holden.they replaced it again and it was perfect after that.I wouldnt have guessed that that would happen.This is a common issue on these cars.
It might be worth looking into ,it seems you have looked at most other things.