Cutting out!!!!

[RollerGirl77]

My VT Acclaim, 99' V6 keeps dying on me while i'm driving. It started a couple of weeks ago, I use unleaded petrol in it, as I was told to when I bought it in August. It does it randomly, nothing seems to trigger it. I went in and got a diagnostic check done and it came back with nothing. Sometimes it starts right away after it cuts out, other times it takes up to 30mins to start it again. When it doesn't go, it still tries to turn over but just won't start up.... its not cool coz one day its gonna cut out on me while i'm sitting at lights......lol..what the hell is wong with my car???? When car is going its smooth as.....HELP

[anarklov3r]

Is it a V6? If so, its probably just your CAS (Crank angle sensor). Its basically a device that sits on the front of your engine block, behind your harmonic balancer, and tells your computer what position your crank is in, so it knows when to inject fuel. These fail commonly after 150,000 kms.

THe part itself isnt very expensive (can be found for <$100), but in order to replace it you need to take off your balancer, and you need a special tool for that.

Easiest way to test if it is your CAS, next time the car dies, and wont start, carry a bottle of water with you in the car, and pour it all over behind your harmonic balancer (thats the biggest round pulley at the bottom of your engine block looking from the front) You will see a black device with wires coming out of it. If it starts up again after that no problem, then thats your issue!

Hope that helps!

BTW, this is what it looks like

http://www.iquay.com.au/images/ei/10456161-03.jpg

[RollerGirl77]

cool thanks heaps, I had that on my LIST... i've just been reading up on the internet what goes wrong with VT commodores etc.... i'm a female so have not much idea about where to pour the water but I'll give it a go, no doubt it will stall on my way home from work today...lol...

how come the diagnostic check didnt come up with anything??? do you know???

[Tsunamix]

The sensor reads a magnetic pulse generated by an electrode on the crank. If theres no signal, the cars computer assumes the pulse generator is at the far side of crank.

Whats happening is that your CAS is overheating and either shorting or going open circuit. That means it stops reading signals until it cools down. So until it cools down the computer assumes the engine is not able to be started and prevents ignition (think seized crankshaft).

[anarklov3r]

Hence why you pour water on it, and if it starts working, thats def your problem

http://forums.justcommodores.com.au/...engine-bay.jpg
THe big rusted round disc at the bottom of the engine with the bolt on it is your harmonic balancer. Just pour water behind it on both sides (a fair amount) and you should get it !

[Ryder15]

so if this is the case and the CAS does fail. and if you try and start it by holding your foot to the floor, will it sound Flooded and heaps of Smoke and Possible Flames may come out the Exhust.

Im having the same issue at the moment. its kinda annoying because it wont start unless its really cold, and even then its really ruff..??

smae thing?

Sorry for brining up an old topic.. im just Curious on how to fix this.

[PRAVX II S]

To diagnose this problem properly you need the car to be acting up.
Then you can check for things like for spark and use the oscilloscope to check the pattern of the CAS.
It could even be a relay.

[Ryder15]

ah ok because once you rev the shit outta her for about 30 seconds it runs fine lol drive and ildes fine, just starting her when its hot i a Mission

[strgas]

CAS test for v6 auto's , test drive the vehicle with the auto in 1st gear driving at a speed of 55km this will heat up the engine bay nicely and if you can drive for more than 5 kms then your CAS may not be the fault , if the car does stall have some water handy pour the water over the CAS to cool it down and see if the car restarts , then replace your CAS .
fuel pumps are another common fault on the VT's

[wortus]

The sensor reads a magnetic pulse generated by an electrode on the crank. If theres no signal, the cars computer assumes the pulse generator is at the far side of crank.

Whats happening is that your CAS is overheating and either shorting or going open circuit. That means it stops reading signals until it cools down. So until it cools down the computer assumes the engine is not able to be started and prevents ignition (think seized crankshaft).

It's a hall effect device it measures a change in magnetic field (reluctance) and to do this there is a notched metal ring on the back of the harmonic balancer so the metal of the ring going in and out of the CAS as it rotates when the motor turns generates a pulse from this changing magnetic field that the ECU reads so it knows where the engine is with respect to it's rotation so it can trigger the ignition at the right time. It uses this in conjunction with the cam angle sensor. If cold weater on it fixes it just get it changed. There not expensive and best left to a mechanic who can have it changed in less than a hour.